^     r- 

C>  A 


- 


THE  GASOLINE  AUTOMOBILE 


PUBLISHERS     OF     BOOKS      F  O  R_^ 

Coal  Age     ^     Electric  Railway  Journal 

Electrical  World  v  Engineering  News-Record 
American  Machinist  v  The  Contractor 
Engineering 8 Mining  Journal  ^  Power 
Metallurgical  6  Chemical  Engineering 
Electrical  Merchandising 


Geo.  B.  Selden  in  his  "Benzine  Buggy.' 


The  present  day  motor  car. 


(frontispiece) 


ENGINEERING  EDUCATION  SERIES 


THE  GASOLINE  AUTOMOBILE 


PREPARED  IN  THE 

EXTENSION  DIVISION  OF 
THE  UNIVEESITY  OF  WISCONSIN 

BY 
GEORGE  W.  HOBBS,  B.  S. 

INSTRUCTOR  IN    MECHANICAL    ENGINEERING  IN    TH1 

UNIVERSITY  EXTENSION  DIVISION,  THB 

UNIVERSITY  OP    WISCONSIN 


BEN  G.  ELLIOTT,  M.  E. 

I   PROFESSOR  OF    MECHANICAL    ENGIN 
THB   UNIVERSITY  OF  NEBRASKA 


FIRST  EDITION 
EIGHTH  IMPRESSION 


TOTAL  ISSUE,  18,000 


McGRAW-HILL  BOOK  COMPANY,  INC. 

239  WEST  39TH  STREET.  ^  NEW  YORK 


LONDON:  HILL  PUBLISHING  CO.,  LTD. 
6  &  8  BOUVERIE  ST.,  B.  C. 

1915 


COPYRIGHT,  1915,  BY  THE 
MCGRAW-HILL  BOOK  COMPANY,  INC. 


PREFACE 

The  purpose  of  this  book  is  admirably  expressed  in  the  following 
quotation  taken  from  the  Buick  instruction  book:  "To  derive  the 
greatest  amount  of  satisfaction  and  pleasure  from  the  use  of  his  car  the 
driver  should  have  a  complete  understanding  of  the  mechanical  principles 
underlying  its  operation.  Merely  knowing  which  pedal  to  press  or  which 
lever  to  pull  is  not  enough.  The  really  competent  driver  should  under- 
stand what  happens  in  the  various  parts  of  the  car's  mechanism  when  he 
presses  the  pedal  or  pulls  the  lever.  He  should  know  the  cause  as  well 
as  the  result." 

When  we  consider  the  complexity  of  modern  automobiles  from  a 
mechanical  standpoint,  with  the  duties  that  are  required  of  them, 
together  with  the  fact  that  the  great  majority  of  them  are  operated  by 
men  with  little  or  no  experience  in  the  handling  of  machinery,  the 
automobile  stands  as  one  of  the  most  remarkable  machines  that  the 
ingenuity  of  man  has  ever  produced.  The  operating  expense  of  the 
automobile  has  already  assumed  a  large  place  in  the  budget  of  the 
American  people.  Although  it  is  so  built  that  the  owner  may  secure  good 
service  from  his  automobile  with  very  little  knowledge  of  its  construction, 
still  it  is  evident  that  an  intimate  acquaintance  with  its  details  should 
enable  him  to  secure  better  service  at  less  expense  and  at  the  same  time 
to  prolong  the  useful  life  of  the  car. 

It  is  with  the  hope  of  increasing  the  pleasure  of  automobile  ownership 
and  reducing  the  trouble  and  expense  of  operation  that  this  book  is 
offered.  It  is  planned  primarily  for  use  in  the  University  Extension  work 
in  Wisconsin,  for  the  instruction  of  those  who  drive,  repair,  sell,  or  other- 
wise have  to  do  with  motor  cars.  It  is  largely  the  outgrowth  of  a  series 
of  lectures  on  the  subject  which  were  given  in  twenty-three  cities  of 
Wisconsin  during  the  past  winter. 

The  thanks  of  the  authors  are  especially  due  to  Mr.  M.  E.  Faber  of 
the  C.  A.  Shaler  Co.  for  assistance  in  preparing  the  section  dealing  with 
tire  troubles,  to  Prof.  Earle  B.  Norris  for  much  of  the  chapter  on  Engines 
and  for  editing  the  manuscript  and  reading  the  proof,  and  to  the  many 
manufacturers  who  have  liberally  assisted  in  the  preparation  of  the  work 
by  supplying  their  cuts  and  other  material. 

G.  W.  H. 
MADISON,  Wis., 
Sept.  15,  1915. 


vu 


CONTENTS 

CHAPTER  I 
GENERAL  CONSTRUCTION 

ART.  PAGE 

1.  The  steam  propelled  car 1 

2.  The  electric  car 1 

3.  The  gasoline  car 2 

4.  Types  of  cars 2 

5.  The  chassis 2 

6.  The  frame .  6 

7.  The  springs 6 

8.  The  front  axle : 8 

9.  The  steering  gear 10 

10.  The  rear  axle 12 

11.  The  differential 13 

12.  The  power  plant  and  transmission 14 

13.  The  torque  arm 15 

14.  Strut  rods 16 

15.  Brakes 16 

16.  Wheels 18 

17.  Tires      19 

18.  Rims 20 

19.  The  speedometer  drive       21 

20.  Control  systemr       23 

CHAPTER  II 

ENGINES 

21.  What  is  an  explosion? 25 

22.  Cycles 25 

23.  The  four-stroke  cycle 26 

24.  The  order  of  events  in  four-stroke  engines 27 

25.  The  mechanism  of  four-stroke  engines 28 

26.  Valve  timing  and  setting 29 

27.  Valves 30 

28.  Valve  arrangements 33 

29.  The  Knight  engine 34 

30.  The  rotary  valve 34 

31.  Two-stroke  engines 35 

32.  The  flywheel 38 

33.  Ignition .39 

34.  Clearance  and  compression ' 39 

35.  Piston  displacement 39 

36.  Cylinder  cooling 40 

37.  The  muffler • 40 

38.  Horse  power  of  engines 41 

ix 


x  CONTENTS 

CHAPTER  III 
POWER-PLANT  GROUPS  AND  TRANSMISSION  SYSTEMS 

39.  Single-  and  multi-cylinder  engines 43 

40.  Power  plant  and  transmission  arrangements ".    .    .    .  44 

41.  Modern  automobile  power  plants 50 

42.  Constructional  features  of  four-  and  six-cylinder  engines 56 

43.  Eight-  and  twelve-cylinder  power  plants 60 

44.  Clutches 64 

45.  Change  gear  sets 66 

46.  Planetary  gearing 67 

47.  Universal  joints  and  drive  shaft 69 

48.  Final  drive 70 

49.  Types  of  live  rear  axles      71 

CHAPTER  IV 
FUELS  AND  CARBTJRETTING  SYSTEMS 

50.  Hydrocarbon  oils 75 

51.  Fractional  distillation  of  petroleum 75 

52.  Principles  of  vaporization 76 

53.  Heating  value  of  fuels 79 

54.  Gasoline  gas  and  air  mixtures 79 

55.  Principles  of  carburetor  construction 79 

56.  Schebler,  model  L  carburetor 82 

57.  Schebler,  model  R 84 

58.  The  Holley  model  H  carburetor 86 

59.  Holley  model  G 87 

60.  Stewart  model  25 89 

61.  Kingston  model  L 90 

62.  Marvel  carburetor 91 

63.  Stromberg,  model  H 94 

64.  Zenith  model  L 94 

65.  Rayfield  model  G 95 

66.  Carter  model  C 97 

67.  General  rules  for  carburetor  adjustment 98 

68.  Carburetor  control  methods      99 

69.  The  gravity  feed  system 99 

70.  The  pressure  feed  system 100 

71.  The  vacuum  feed  system 100 

72.  Intake  manifolds 102 

73.  Care  of  gasoline 102 

CHAPTER  V 
LUBRICATION  AND  COOLING 

74.  Friction  and  lubricants 103 

75.  Cylinder  oils 104 

76.  Viscosity 104 


CONTENTS  xi 

AET.  PAGE 

77.  Flash  point 104 

78.  Fire  test  and  cold  test 104 

79.  General  notes  on  lubrication 104 

80.  Splash  system  of  engine  lubrication 106 

81.  Splash  system  with  circulating  pump      106 

82.  Full  forced  feed  system      Ill 

83.  Mixing  the  oil  with  the  gasoline 113 

84.  Selection  of  a  lubricant 113 

85.  Directions  for  lubrication 114 

86.  Cylinder  cooling 117 

87.  Water  cooling  systems 117 

88.  Air  cooling 122 

89.  Cooling  solutions  for  winter  use 123 

CHAPTER  VI 

BATTERIES  AND  BATTERY  IGNITION 

90.  Fundamental  electrical  definitions 127 

91.  Direct  and  alternating  current 127 

92.  Dry  batteries 128 

93.  Storage  batteries 128 

94.  Series  and  parallel  connections 129 

95.  Battery  connections  for  ignition  purposes 130 

96.  Simple  battery  ignition  system 130 

97.  The  three  terminal  coil 132 

98.  Timers 135 

99.  Spark  plugs 135 

100.  Master  vibrators 136 

101.  The  high  tension  distributor  system 137 

102.  The  Connecticut  automatic  ignition  system 139 

103.  The  Atwater  Kent  system 141 

104.  The  Westinghouse  ignition  system 144 

105.  The  Delco  system  of  ignition 147 

106.  The  Remy-Studebaker  ignition  system 149 

107.  Spark  advance  and  retard 151 

108.  Automatic  spark  advance     151 

CHAPTER  VII 

MAGNETOS  AND  MAGNETO  IGNITION 

109.  Principles  of  magnetism : 153 

110.  Mechanical  generation  of  current 155 

111.  Low  and  high  tension  magnetos 156 

112.  Armature  and  inductor  types 156 

113.  Remy  model  P  magneto 157 

114.  The  Connecticut  magneto 160 

115.  Dual  ignition  systems 160 

116.  Eisemann  high  tension  dual  ignition 161 

117.  Eisemann  automatic  spark  control 163 

118.  The  K-W  high  tension  magneto 163 


rii  CONTENTS 

ABT.  PAGS 

119.  The  Dixie  magneto 16f> 

120.  The  Bosch  high  tension  magneto 167 

121.  The  Bosch  dual  system 170 

122.  Bosch  two-independent  system 173 

123.  The  Ford  magneto  and  ignition  system 174 

124.  Magneto  speeds 175 

125.  Timing  the  magneto 176 

126.  Battery  vs.  magneto  ignition 177 

127.  General  suggestions  on  magnetos 177 

128.  Common  magneto  ignition  definitions 177 

CHAPTER  VIII 
STARTING  AND  LIGHTING  SYSTEMS 

129.  Starting  on  the  spark 179 

130.  Mechanical  starters 180 

131.  Air  starters 180 

132.  Acetylene  starters 180 

133.  Electric  starters 181 

134.  Storage  batteries 181 

135.  Battery  charging • 185 

136.  Wiring  systems 187 

137.  The  Ward-Leonard  system 187 

138.  The  Delco  system 190 

139.  Gray  and  Davis  starting  and  lighting  systems 193 

140.  Wagner  starting  and  lighting  system 197 

141.  The  Westinghouse  single-unit  system 199 

142.  Westinghou.se  two-unit  system 200 

143.  The  U.  S.  L.  electric  starting  and  lighting  system 204 

144.  Jesco  single-unit  electric  starter  and  lighter 205 

145.  Care  of  starting  and  lighting  apparatus. 207 

146.  Starting  motor  troubles 208 

147.  Generator  troubles 209 

148.  Battery  troubles 209 

149.  Winter  care  of  batteries 209 

150.  "Don'ta"  on  starting  equipment 210 

CHAPTER  IX 

AUTOMOBILE  TROUBLES  AND  REMEDIES 

151.  Classification  of  troubles 213 

152.  Power  plant  troubles 214 

153.  Mechanical  troubles  in  engine 216 

154.  Carburetion  troubles 221 

155.  Ignition  troubles 223 

156.  Lubricating  and  cooling  troubles      226 

157.  Starting  and  lighting  troubles 228 

158.  Transmission  troubles 228 

159.  Chassis  troubles  .                                                                                                .  229 


CONTENTS  xiii 


CHAPTER  X 
OPERATION  AND  CARE 

ART.  PAGE 

160.  Preparations  for  starting 231 

161.  Cranking 231 

162.  How  to  drive 232 

163.  Use  of  the  brakes 233 

164.  Speeding 234 

165.  Care  in  driving 234 

166.  Driving  in  city  traffic 235 

167.  Skidding       236 

168.  Knowing  the  car 237 

169.  The  spring  overhauling 238 

170.  Washing  the  car 240 

171.  Care  of  tires 240 

172.  Tire  troubles 243 

173.  Figuring  speeds 247 

174.  Interstate  regulations 248 

175.  Canadian  regulations 249 

176.  Touring  helps-route  books 250 

177.  Cost   records 250 

INDEX  .  .  255 


THE  GASOLINE  AUTOMOBILE 

CHAPTER  I 
GENERAL  CONSTRUCTION 

Automobiles  may  be  classified  according  to  the  type  of  power  plant 
used,  as  steam,  electric,  and  gasoline;  or  they  may  be  divided  into  two 
classes  according  to  use,  as  pleasure  cars  and  commercial  cars. 

1.  The  Steam  Propelled  Car. — The  steam  engine  has  the  advantage  of 
-flexibility.     All  operations  such  as  starting,  stopping,  reversing,   and 

acquiring  changes  of  speed  can  be  done  directly  by  throttle  control. 
By  opening  or  closing  the  throttle,  more  or  less  steam  is  supplied  to  the 
engine,  and  the  power  is  increased  or  decreased  in  proportion.  When 
climbing  a  hill,  all  that  is  necessary  to  do  is  to  give  the  engine  more  steam 
and  consequently  more  power.  The  advantage  of  the  steam  engine  in 
being  able  to  start  under  load  eliminates  the  clutch  and  also  the  trans- 
mission or  change  speed  gears,  the  engine  being  connected  directly  to 
the  rear  axle. 

The  disadvantage  of  the  steam  engine  is  that  it  is  necessary  to  fire  up 
before  starting,  in  order  to  generate  enough  steam  to  run  the  engine  and 
propel  the  car.  The  steam  machine  requires  large  quantities  of  water 
to  form  the  steam  and  that  means  frequent  refilling  of  the  water  tank. 
They  also  require  constant  attention  to  the  water  and  fuel  pumps.  The 
burning  of  the  fuel  under  a  boiler  to  generate  the  steam  introduces  an 
element  of  danger  from  fire  and  also  makes  the  steam  plant  less  efficient 
than  the  internal  combustion  engine. 

2.  The  Electric  Car. — The  advantages  of  the  electric  car  are  similar  to 
those  of  the  steam  car  inasmuch  as  it  is  very  flexible  and  can  be  controlled 
entirely  by  the  controlling  levers.     By  cutting  out  or  in  resistance,  more 
or  less  current  is  supplied  to  the  motor  and  the  power  of  the  motor  is 
proportional  to  the  flow  of  the  current.     The  electric  car  is  especially 
adapted  to  the  use  of  women  and  children  in  cities.     It  is  easy  riding, 
clean,  and  very  quiet. 

The  disadvantages  are  that  it  is  not  suitable  for  long  drives,  heavy 
roads,  or  hilly  country.  On  one  charge  of  the  battery  the  average  car 
will  run  from  50  to  100  miles^  ^depending  on  the  speed  and  condition 
of  the  roads.  If  the  car  is  run  at  high  speed,  the  battery  will  not 

1 


2  THE  GASOLINE  AUTOMOBILE 

drive  the  car  as  far  as  it  will  when  running  at  moderate  rate.  This 
car  is  also  limited  to  localities  where  there  are  ample  facilities  for  charging 
the  storage  batteries. 

3.  The  Gasoline  Car. — The  gasoline  engine  is  much  more  economical 
than  either  the  steam  or  electric,  and  after  being  once  started  has  great 
flexibility.     It  is  also  better  adapted  for  touring  purposes  than  either 
of  the  others  and  does  not  require  any  more  attention  from  the  operator. 
The   average    car    carries  enough  fuel  to    run    it  200    to    400   miles 
without  a  stop  and  then  it  is  necessary  to  fill  the  gasoline  tank  only, 
with  an  occasional  quart  or  two  of  water  for  the  radiator.     With  proper 
care,  the  engine  will  run  as  long  as  the  gasoline  supply  and  electrical 
system  will  hold  out. 

The  disadvantages  of  the  gasoline  engine  as  compared  with  the  steam 
engine  or  electric  motor  are,  first,  the  gasoline  engine  is  not  self-starting; 
and,  second,  it  lacks  overload  capacity.  This  means  that  some  method  of 
changing  the  speed  ratio  of  the  engine  to  the  rear  wheels  is  necessary  in 
order  to  acquire  extra  power  for  climbing  hills,  for  heavy  roads,  and  also 
for  reversing  the  car,  as  it  is  not  possible  to  reverse  the  ordinary  four- 
stroke  automobile  engine.  The  gasoline  engine  will  not  start  under  load, 
which  necessitates  the  use  of  a  clutch,  so  that  the  engine  can  be  started 
and  speeded  up  before  any  load  is  thrown  on.  Apparently  there  are  a 
great  many  disadvantages  to  the  gasoline  engine  but  in  reality  they  are 
very  few,  for  with  the  proper  handling  of  the  spark  and  throttle  control- 
ling levers  it  is  not  necessary  to  keep  continually  changing  gears.  The 
speed  change  lever  need  not  be  used  except  for  starting,  stopping,  hill* 
climbing,  and  on  bad  roads. 

4.  Types  of  Cars. — In  general,  the  parts  of  the  pleasure  and  commercial 
cars  are  the  same  except  that  the  pleasure  cars  are  built  much  lighter  than 
the  commercial  cars.     In  the  pleasure  car  everything  is  planned  for 
comfort  and  speed,  while  the  commercial  car  is  built  for  heavy  loads  and 
is  generally  intended  to  be  driven  at  low  speed. 

The  principal  body  types  of  pleasure  cars  are,  the  limousine,  the 
touring  car,  the  coupe,  and  the  roadster,  as  shown  in  Fig.  1. 

The  commercial  cars  are  built  for  light,  medium,  and  heavy  duty.  A 
few  of  the  commercial  types  are  shown  in  Fig.  2. 

The  cycle  car  is  a  name  commonly  given  to  small  cars  which  have  less 
than  70  cu.  in.  piston  displacement  or  a  tread  of  less  than  56  in. 

5.  The  Chassis. — The  principal  parts  of  the  gasoline  automobile  are 
the  frame,  springs,  axles,  wheels,  power  plant  and  auxiliaries,  clutch, 
transmission  system,  controlling  apparatus  and  body.     The  chassis,  as 
shown  in  Fig.  3,  includes  all  parts  with  the  exception  of  the  body  and  its 
accessories.    The  functions  and  types  of  these  parts  will  be  taken  up 
separately. 


GENERAL  CONSTRUCTION 


THE  GASOLINE  AUTOMOBILE 


JLJLJ 


HEAVY    TRUCK 


LIGHT     TRUCK 


MEDIUM  TRUCK 


2.— Types  of  commercial  canp, 


GENERAL  CONSTRUCTION 


Radiator 


Power  plant 
-Clutch 
•Universal  joint 


-Control  levers 
-Drive  shaft 


Torque  crrm- 

or 
Torque  rod 


Muffler 

Brake  equalizers 
3 rake 


-Storage  baffery 

mmmm 
Universal  joint 

Change  aears 
Brakes 


FIG.  3.— Chassis  of  the  Studebaker  "Six. 


6  THE  GASOLINE  AUTOMOBILE 

6.  The  Frame. — The  automobile  frame  is  a  very  important  part  of 
the  car,  due  to  the  fact  that  it  supports  the  power  plant,  transmission 
mechanism,  body,  etc.  The  frame  is  attached  to  the  springs,  which  in 
turn  are  fastened  to  the  axles.  Frames  are  made  either  of  wood  or  metal 
.or  a  combination  of  the  two.  The  metal  frames  are  usually  of  channel- 
section  steel.  The  wooden  frames  may  be  either  of  the  solid  timber  type 
or  of  laminated  strips  glued  together  and  sometimes  reinforced  by  steel 
strips.  This  type  is  very  strong  and  light  and  does  not  transmit  so  much 


FIG.  4. — Channel  steel  frame. 


of  the  vibration  as  the  steel  frame.  Figure  4  shows  a  pressed  steel  channel- 
section  frame.  Figure  5  shows  a  frame  made  from  second-growth  ash  and 
used  on  the  Franklin  car. 

7.  The  Springs. — The  frame  of  the  automobile  is  supported  by 
laimated  leaf  springs.  Coil  springs  are  used  only  in  places  where  a  great 
deal  of  strength  is  needed  in  a  small  space  and  where  quick  action  is 
required.  The  springs  under  the  frame  of  an  automobile  must  be  gradual 


FIG.  5. — Franklin  wood  frame  construction. 

and  easy  in  their  action,  and  this  is  why  the  laminated  leaf  spring  is  used. 
The  strength  and  resilience  of  the  leaf  spring  can  be  varied  by  changing 
the  number  of  leaves  or  by  varying  the  width  or  length  of  the  leaf.  It 
also  has  an  advantage  over  the  coil  spring  in  that  if  one  leaf  breaks  the 
spring  is  still  serviceable,  while  in  a  coil  spring  if  a  coil  breaks  the  spring 
is  no  longer  of  any  use. 

The  laminated  spring  is  built  up  of  a  number  of  leaves  varying  in 
length,  the  longest  leaf  being  on  the  concave  side  of  the  spring  and  the 


GENERAL  CONSTRUCTION 


g  THE  GASOLINE  AUTOMOBILE 

other  leaves  built  on  this  one  in  the  order  of  their  length.  The  ends  of 
the  long  leaf  are  bent  around  to  form  eyes  so  that  they  can  be  fastened  to 
the  frame  by  a  clevis  or  other  means. 

The  laminated  leaf  springs,  as  shown  in  Fig.  6,  are  built  in  the  follow- 
ing forms:  cantilever,  semi-elliptic,  three-quarter  elliptic,  full-elliptic, 
and  platform  springs. 

The  Cantilever  spring  is  fastened  flexibly  to  the  frame  at  one  end  and 
the  center  and  carries  the  axle  at  the  other  end.  There  is  another 
type  of  (jantilever  spring  which  has  a  single  rigid  fastening  to  the  frame. 
This  is  also  called  a  quarter-elliptic  spring. 

The  (semi-elliptic  spring  usually  has  its  center  fastened  to  the  axle 
while  thl  two  ends  support  the  frame.  This  type  of  spring  is  generally 
used  to  ^upport  the  front  end  of  the  car,  because  this  type  has  the  least 
amount  of  side-sway.  Since  the  front  axle  is  used  for  steering  purposes,  a 
great  amount  of  flexibility  is  not  desired. 

The  three-quarter  elliptic  spring  consists  of  a  semi-elliptic  member, 
to  one  end  of  which  is  attached  a  quarter-elliptic  member.  This  type 
is  supported  in  the  middle  of  the  semi-elliptic  spring  and  is  connected 
to  the  frime  at  one  end  of  the  semi-elliptic  and  the  free  end  of  the  quarter- 
elliptic  sbrings. 

The  ifull-elliptic  spring  consists  of  two  semi-elliptic  springs  con- 
nected together  at  the  end,  supported  at  the  middle  of  one  semi-elliptic 
and  carrying  the  load  at  the  middle  of  the  other.  Either  the  three- 
quarter  or  the  full-elliptic  types  have  greater  flexibility  than  the  semi- 
elliptic  tiype. 

The  platform  spring  consists  of  three  semi-elliptic  springs  fastened 
together.  Two  of  the  members  are  parallel  to  the  sides  of  the  car  arid 
the  third  is  inverted  and  is  parallel  to  the  cross  members.  The  car  frame 
is  attached  to  the  front  end  of  the  side  members  and  to  the  middle  of  the 
cross  member.  The  middle  of  the  side  members  rests  on  the  spring 


8.  The  Front  Axle. — The  front  axle  consists  of  the  center,  the  knuckles, 
a  steering  arm,  a  third  arm,  a  plain  arm,  and  the  tie  rod.  The  centers 
are  either  I-beam,  as  shown  in  Fig.  7  or  tubular  as  in  Fig.  8,  and  they 
may  be  either  straight  or  dropped  center  types.  Square  centers  are 
sometimes  used  on  heavy  trucks. 

The  }-beam  centers  are  made  either  of  drop  forgings  or  of  cast  steel 
and  are  heat-treated  to  do  away  with  brittleness  and  give  strength  and 
toughness.  The  tubular  centers  and  tie  rods  are  made  from  the  best 
high-grade  seamless  steel  tubing  and  the  yokes  are  either  pinned  or 
brazed  on  the  ends  of  the  tubes.  In  the  I-beam  centers  the  yokes  form 
a  part  of  the  forging  or  casting.  The  I-beam  construction  is  the  strong- 
est but  is  not  quite  so  flexible  as  the  tubular  center. 


GENERAL  CONSTRUCTION  9 

The  front  wheels  are  fastened  on  the  spindle  of  the  knuckle  and  run 
on  cup-and-cone  ball  bearings  or  on  roller  bearings  as  shown  in  Fig.  7. 
The  spindle  is  set  so  that  the  front  wheels  have  a  camber  of  about  2  in., 
that  is,  the  tops  of  the  wheels  are  about  2  in.  farther  apart  than  the 


FIG.  7. — I-beam  front  axle  construction. 

bottoms  of  the  wheels.  This  is  to  conform  to  the  crown  of  the  road  and 
to  bring  the  point  of  contact  between  the  tire  and  the  road  in  line  with 
the  king-bolt. 

In  order  to  make  the  car  steer  easier  and  have  a  tendency  to  run 
straight  ahead,  the  front  wheels  should  toe  in  from  %  to  ^  in.  This  is 
done  by  adjusting  the  length  of  the  tie  rod. 


FIG.  8. — Tubular  front  axle. 

The  knuckles  are  fastened  in  the  axle  yokes  by  king-bolts  and  are 
free  to  swing  about  35°  either  way  from  the  center  line  of  the  axle. 
This  is  necessary  in  order  to  allow  the  wheels  to  follow  a  curve  when  turn- 
ing. Between  the  top  of  the  axle  yoke  and  the  knuckle  there  should 


10 


THE  GASOLINE  AUTOMOBILE 


be  a  ball  or  roller  bearing  or  a  renewable  bronze  washer  to  carry  the 
load  and  yet  allow  the  knuckle  to  turn  easily. 

The  king-bolt  should  fit  in  a  bronze  bearing  in  order  to  insure  easy 
movement  and  a  small  amount  of  wear.  The  steering  and  third  arms, 
which  are  generally  combined  in  a  single  forging,  are  keyed  to  one 
knuckle.  The  third  arm  is  connected  by  the  tie  rod  to  the  plain  arm, 
which  is  keyed  to  the  other  knuckle.  The  general  layout  of  the  steering 
apparatus  is  shown  in  Fig.  9.  The  steering  arm  is  connected  by  the  drag 
link  to  the  pitman  arm  or  steering  lever  on  the  base  of  the  steering 


gear. 


Steerinq   wheel 

Sfeer/na  column -: 


«        Pitman  arm 
—-Drag  link 


Fig.  9. — Arrangement  of  steering  apparatus. 


9.  The  Steering  Gear. — The  steering  gear  is  the  part  of  the  mechan- 
ism that  operates  on  the  knuckles  to  turn  the  front  wheels  in  response 
to  movements  of  the  hand  wheel. 

Figure  10  shows  the  essential  parts  of  a  double  worm  steering  gear. 
Inside  the  steering  column  is  the  steering  tube,  the  upper  end  of  which 
is  connected  to  the  hand  wheel  while  the  lower  end  carries  a  double- 
threaded  worm.  The  worm  meshes  with  two  half-nuts,  one  with  a  right- 
hand  and  the  other  a  left-hand  thread.  Two  rollers,  which  are  attached 
to  the  yoke  that  operates  the  pitman  arm  or  steering  lever,  bear  against 
the  lower  ends  of  the  half-nuts.  The  operation  is  as  follows:  Turning 
the  hand  wheel  turns  the  tube  and  worm  in  the  same  direction,  which 
causes  one  half-nut  to  rise  and  the  other  to  descend.  This  pushes  one 
roller  down  and  lets  the  other  rise.  The  yoke  is  given  the  same  motion 


GENERAL  CONSTRUCTION 


11 


and  transmits  it  to  the  pitman  arm,  which  pushes  or  pulls  on  the  drag 
link  and  thus  turns  the  knuckle  and  wheels. 


Sector 


Spark  lever 
/     Throttle,  lew 

X        js' 


rod 


—Stationary  tube 

•Throft/e  fube 

"•Adjusting  nut 
— Grease  plug 


, Throttle  gear 

— -  -fy&r/c  a  ear 


FIG.  10. — Double  worm  steering  mechanism. 

Figure  11  shows  the  worm-and-gear  type.  The  worm  is  fastened  to  the 
steering  tube  and  is  turned  with  the  hand  wheel.  The  gear  shaft  carries 
the  pitman  arm,  which  connects  to  the  knuckle  steering  arm  by  the 
drag  link. 


12  THE  GASOLINE  AUTOMOBILE 

These  steering  gears  are  non-reversible,  because  while  the  action 
of  the  hand  wheel  is  readily  transmitted  to  the  front  wheels  the  jarring 
of  the  front  wheels  on  rough  roads  can  not  be  transmitted  back  to  turn 
the  hand  wheel. 


Grease  Cup 
Worm 


Gear 


FIG.  11. — Worm-and-gear  steering  mechanism. 


10.  The  Rear  Axle. — The  rear  axle  must  carry  this  end  of  car  and 
also  provide  means  of  giving  power  to  the  rear  wheels  to  propel  the  car. 
This  is  done  in  two  general  ways,  and  the  corresponding  types  of  axles 
are  called  "dead"  and  "live"  axles. 

Figure  12  shows  a  truck  chassis  with  a  dead  rear  axle.  It  is  somewhat 
similar  in  construction  to  the  ordinary  wagon  axle,  as  it  is  made  up  of  a 


FIG.  12. — Heavy  truck,  chassis  with  dead  rear  axle. 


solid  bar  with  spindles  machined  on  the  ends  for  the  wheel  bearings. 
The  wheels  have  large  sprockets  on  the  inside  which  are  driven  by  chains 
from  other  sprockets  on  the  ends  of  a  "jackshaft"  near  the  middle  of  the 
car.  This  type  of  axle  is  used  principally  on  heavy  trucks  where  it  is 


GENERAL  CONSTRUCTION  13 

necessary  to  have  a  solid  construction  and  provide  for  a  large  reduction 
in  speed. 

For  pleasure  cars,  the  live  axle  is  generally  used.  The  general 
arrangement  of  a  car  with  a  live  axle  was  shown  in  Fig.  3.  In  Fig.  13  is 
shown  in  detail  the  construction  of  a  typical  live  axle.  In  this  type  the 
axle  turns  and  drives  the  rear  wheels  with  it.  The  axle  is  surrounded 
by  a  stationary  housing  which  supplies  the  bearings  for  the  wheels  and 
the  axle  and  which  also  supports  the  car  through  the  springs.  The 
live  axle  receives  its  power  near  the  center,  usually  through  a  set  of 
bevel  gears  which  give  the  desired  speed  reduction  and  also  make  the 
necessary  right  angle  change  in  the  power  transmission. 


BE4R/NG5 


DffUM 


FIG.  13. — Live  rear  axle. 

11.  The  Differential. — Some  provision  has  to  be  made  to  drive  the 
rear  wheels  positively  in  either  direction  and  yet  allow  one  wheel  to  run 
ahead  of  the  other  when  turning  a  corner.  This  is  done  by  dividing  the 
live  rear  axle  at  the  center  and  connecting  the  two  halves  by  a  differential 
gear,  the  details  of  which  are  shown  in  Fig.  14.  Each  half  of  the  live 
axle  (called  the  main  shaft  in  Fig.  14)  has  a  bevel  gear  on  its  inner  end. 
These  bevel  gears  face  each  other  and  are  called  the  differential  gears. 
They  are  connected  by  from  two  to  four  differential  pinions  spaced  at 
equal  distances  around  the  circle.  The  power  is  applied  at  the  centers 
of  these  differential  pinions  so  that  they  act  like  the  doubletrees  or 
eveners  on  a  team  of  horses,  allowing  one  wheel  to  run  ahead  of  another 
or  to  lag  behind  but  still  maintaining  an  even  pull  on  the  two  differential 
gears.  Referring  to  Fig.  14,  the  power  from  the  engine  is  brought  back 
to  the  driving,  pinion  and  this  delivers  it  to  the  large  gear  called  the  bevel 
ring.  This  bevel  ring  is  fastened  to  the  differential  case,  which,  therefore, 
receives  the  power  from  the  bevel  ring.  The  differential  case  turns  the 
spider  with  it  and,  as  this  spider  carries  the  differential  pinions,  these 
pinions  are  carried  around  with  a  force  applied  at  their  centers.  On  a 


14 


THE  GASOLINE  AUTOMOBILE 


straight  road  the  differential  case,  the  spider,  the  differential  pinions 
and  the  differential  gear  all  revolve  as  one  mass  and  there  is  no  internal 
action  in  the  differential.  The  differential  pinions  pull  equally  on  the  two 
differential  gears  on  each  side  of  them  and  they  all  revolve  together.  In 


FIG.  14. — Differential  gear. 

turning  a  corner  the  outer  wheel  has  farther  to  go  and  hence  must  run 
faster.  This  makes  the  one  differential  gear  turn  faster  than  the  other. 
This  causes  the  differential  pinions  to  revolve  on  their  axes,  but  they 
still  continue  to  deliver  power  equally  to  the  two  wheels. 


FIG.  15. — Arrangement  of  power  plant  and  transmission  system. 

12.  The  Power  Plant  and  Transmission'.— Figure  15  shows  a  typical 
arrangement  of  the  power  plant  and  the  power  transmission  system. 
The  engine  is  generally  placed  in  the  front  end  of  the  car,  both  for  ac- 
cessibility and  to  balance  the  weight  of  the  passengers  in  the  rear  part 


GENERAL  CONSTRUCTION  15 

of  the  car.  The  engine  is  the  most  important  part  of  the  car.  Its 
purpose  is  to  transform  the  heat  energy  of  gasoline  into  mechanical 
energy  at  the  crank  shaft  for  the  purpose  of  driving  the  car.  The  power 
is  delivered  to  the  flywheel,  from  which  the  clutch  takes  it  and  passes  it 
back  to  the  transmission.  In  the  transmission  case  is  a  system  of  gears 
for  reducing  the  speed  from  the  engine  and  increasing  the  turning  force 
for  starting  purposes  or  for  heavy  driving,  as  in  sand  or  on  hills. 

The  power  plant  is  mounted  on  the  frame  of  the  car,  while  the  rear 
wheels  which  are  to  finally  receive  and  use  the  power  are  flexibly  con- 
nected to  the  frame  by  springs.  We  must,  therefore,  have  a  flexible 
arrangement  for  taking  the  power  from  the  power  plant  to  the  rear 
axle.  This  is  usually  accomplished  by  means  of  a  propeller  shaft  and 
one  or  two  universal  joints  (see  Fig.  15).  A  universal  joint  is  merely  a 
double-hinged  shaft  connection  (see  Fig.  16)  permitting  the  lower  end  of 
the  propeller  shaft  to  swing  at  will  with  the 
rear  axle  and  yet  receive  power  from  the 
engine. 

In  the  t,car  of  Fig.  15  the  engine  and 
transmission  are  carried  in  the  frame  of  the 
car  and  the  first  universal  lies  just  back  of  the 
transmission.  In  the  car  of  Fig.  3  the  trans- 
mission with  its  change  gears  is  placed  just  in  „ 

Tii          FlG-  I6- — Universal  joint, 
front  of  the  rear  axle  and  is  fastened  solidly 

to  the  rear  axle  housing.  This  places  both  universal  joints  and  the 
propeller  shaft  between  the  engine  and  the  transmission. 

In  addition  to  the  engine  proper,  the  power  plant  contains  a  number 
of  accessories  necessary  for  the  operation  of  the  engine,  such  as  the 
lubricating  system,  the  ignition  system,  the  carburetor,  the  cooling  system, 
and  the  starting  system.  In  the  so-called  unit  power  plant  the  clutch 
and  change  gears  are  contained  in  a  single  unit  with  the  engine.  All 
these  accessories  will  be  taken  up  in  the  later  chapters. 

In  heavy  trucks  the  system  of  power  transmission  is  somewhat 
different  from  the  pleasure  car  system  just  described.  The  power  from 
the  engine  is  carried  through  the  clutch  and  back  to  the  transmission 
located  in  the  center  of  the  chassis,  as  shown  in  Fig.  12.  Here  the  power 
is  turned  at  right  angles  in  the  rear  part  of  the  transmission  and  is  given 
to  a  jackshaft  lying  across  the  car.  The  sprockets  on  the  outer  ends  of 
this  jackshaft  drive  the  rear  wheels  through  two  chains.  No  universal 
joints  are  needed  in  the  final  drive,  as  the  chains  allow  for  the  free  motion 
of  the  rear  axle. 

13.  The  Torque  Arm. — When  the  brakes  are  used  in  stopping  a 
car,  the  brakes,  being  carried  by  the  rear  axle  housing,  tend  to  carry  this 
Jiousing  around  with  the  wheels,  likewise,  the  action  of  *he  propeller 


16  THE  GASOLINE  AUTOMOBILE 

shaft  and  the  bevel  pinion  in  driving  the  rear  axle  (see  Fig.  14)  tend  to 
turn  the  axle  housing  over  backward  with  the  same  force  that  is  exerted 
on  the  bevel  ring.  This  twisting  action  or  "torque"  must  be  taken 
care  of  in  some  way.  This  can  be  done  by  torsion  rods  as  in  Fig  15, 
or  by  a  single  bar  called  a  torque  arm  or  by  a  torsion  tube  around  the 
propeller  shaft,  or  it  can  be  left  entirely  to  the  springs  to  take  care  of  this 
action.  If  the  torque  is  taken  up  by  a  housing  around  the  propeller 
shaft  as  in  Fig.  17,  this  tube  is  called  the  "third  member"  of  the  rear  axle 
system  and  is  securely  bolted  to  the  rear  axle  housing.  This  system  does 
away  with  one  universal  joint,  as  only  one  at  the  front  extremity  of  the 
propeller  shaft  is  used. 


Strut  roof- 


FIG.  17. — Rear  axle  with  torque  tube  and  strut  rods. 


14.  Strut  Rods. — In  order  to  preserve  the  alignment  of  the  wheels  or 
to  keep  one  wheel  from  getting  ahead  of  the  other,  strut  rods  are  fastened 
to  the  brake  flanges  or  spring  seats,  and  extend  to  the  front  end  of  the 
third  member  as  in  Fig.  17  or  to  some  part  of  the  frame. 

15.  Brakes. — Brakes  which  act  on  the  rear  wheels  are  either  of  the 
contracting  or  expanding  band  type  or  the  expanding  shoe  type. 

Figure  18  shows  the  general  layout.  This  is  known  as  a  double 
internal  type  of  brake.  A  steel  brake  drum  is  fastened  securely  to  the 
wheel.  Both  bands  expand  and  put  pressure  on  the  inside  of  the  drum. 
The  outside  band,  or  the  one  next  the  wheel,  is  the  emergency  brake  and 
is  operated  by  a  hand  lever.  The  other,  the  service  brake,  is  under  the 
control  of  the  driver  through  the  medium  of  the  foot  pedal.  The  brake 
bands  are  carried  by  brake  flanges  near  the  ends  of  the  rear  axle  housing. 
The  two  sets  are  entirely  independent  of  each  other.  Another  type  of 


GENERAL  CONSTRUCTION 


17 


internal  expanding  band  brake  that  uses  two  brake  drums  is  shown  in 
Fig.  19.     The  action  is  similar  to  the  above.     In  this  case  the  smaller 


SERVICE  BRAKE 


SERVICE  BRAKE  LEVER 

EMERGENCY  BRAKE  LEVE 


FIG.  18. — Double  internal  brake  with  single  drum. 


EMERGENCY  BRAKE  LEVER 


FOOT  BRAKE 

EMERGENCY  BRAKE 

NULAfl  BALL  BEARINGS 


RELEASE  SPRINGS 


FIG.  19. — Double  internal  brake  with  two  drums. 

band  is  used  for  the  emergency.     Figure  20  shows  a  type  of  brake  known 
as  the  internal-external  brake.     There  are  two  bands  working  on  the 


18 


THE  GASOLINE  AUTOMOBILE 


Brake 
facing 


same  drum.     One  set  contracts  around  the  outside  of  the  drum  and  the 
other  set  expands  against  the  inner  circumference.     The  outer  band 

constitutes  the  service  or  foot  brake  and 
the  inner  band  the  emergency  brake. 

All  bands,  either  contracting  or  ex- 
panding, are  faced  on  the  rubbing  side 
with  an  asbestos  preparation  that  is 
capable  of  standing  a  great  amount  of 
wear  and  is  not  easily  burned  out.  Some 
types  that  use  the  expanding  shoe  have 
a  cast-iron  shoe  that  is  pressed  against 
the  inside  of  the  steel  drum  on  the  wheel. 
A  typical  mechanism  for  operating 
the  expanding  shoes  or  drums  is  clearly 
shown  in  Fig.  18,  where  the  emergency 
band  is  shown  expanded  while  the  ser- 
vice brake  is  in  the  running  position. 

16.  Wheels. — Automobile  wheels  are 
classified  as  artillery  wheels  (with  wooden 
spokes),  wire  wheels,  and  cast-  or  pressed- 
steel  wheels,  the  latter  being  limited  to 
heavy  duty  trucks. 

Artillery  Wheels. — The   artillery  wheel,  shown  in  Fig.  21,  is  built 
of  second-growth  hickory.     The  spokes  are  fastened  together  at  the 


Expanding 

Contracting 
"" band 


FIG.  20. — Internal-external 
brake. 


Felloe       , 
Demountc 


C/arnp  \ 

rim      Fe//oe.  bane/ 


Demountable  rim         Felloe  band 


FIG.  21.— Artillery  wheel. 


FIG.  22.— Wire  wheel. 


hub  of  the  wheel  by  a  series  of  interlocking  mortise-and-tenon  joints  and 
the  outer  ends  are  turned  down  to  fit  in  holes  in  the  wooden  felloe  band. 


GENERAL  CONSTRUCTION  19 

The  hub  casting,  which  serves  to  hold  the  inner  end  of  the  spokes,  also 
acts  as  the  bearing  housing  for  the  hub  bearings,  on  which  the  wheel 
revolves. 

Wire  Wheels. — The  wire  wheel  is  shown  in  Fig.  22.  On  account  of 
the  scarcity  of  second-growth  hickory,  which  is  the  only  acceptable 
material  for  artillery  wheels,  some  companies  are  building  wire  wheels 
which  are  modifications  of  the  bicycle  wheel.  Wire  spokes  are  inter- 
laced between  the  hub  and  rim  in  such  a  manner  that  the  wheel  is  held 
rigid  and  withstands  both  the  direct  loads  and  side  strains. 

In  the  artillery  wheel,  the  load  is  carried  by  the  spokes  on  the  under 
side.  In  the  wire  wheel,  the  load  is  carried  by  the  spokes  above  the 
hub. 

The  advantages  claimed  by  the  wire  wheel  manufacturers  are  that  the 
wheel  is  reduced  in  weight  about  30  per  cent. ;  is  more  resilient,  which 
makes  an  easier  riding  car;  will  stand  greater  radial  strain;  and  is  fully  as 
strong  as  the  artillery  wheel. 

Wearing  Surfa  ^^^^    /Breaker  Strips 


Inner  Tube 


Piano  W: 


FIG.  23. — Section  of  pneumatic  tire. 


17.  Tires. — The  tires  used  on  pleasure  cars  are  usually  of  the  pneu- 
matic rubber  type.  Some  are  being  filled  with  a  spongy  substance  that 
makes  them  more  of  a  cushion  form  and  some  have  bridges  of  para 
rubber  instead  of  an  air  cushion.  The  lighter  commercial  cars  use  solid 
rubber  tires,  the  heavier  trucks  use  steel  tires,  while  some  are  using 
wooden  blocks.  The  wooden  blocks  and  steel  tires  can  be  used  only  on 
the  very  low-speed  trucks  on  account  of  there  being  no  resilience  in  tires 
of  these  types. 

The  pneumatic  tire  serves  as  a  good  shock  absorber  and  eliminates 
a  large  portion  of  the  road  vibrations  and  jars  before  they  reach  the 
mechanism  of  the  car. 

The  general  construction  of  the  tire  is  shown  in  Fig.  23.  Several 
layers  of  heavy  canvas  (friction  fabric)  are  wound  around  two  circular 
wire  cables  (beads)  in  the  shape  of  a  tire.  This  forms  the  foundation, 


20 


THE  GASOLINE  AUTOMOBILE 


which  is  filled  with  rubber  gum  to  form  the  carcass  of  the  tire.  Around 
the  carcass  the  cushion  is  built,  which  is  an  extra  thickness  of  com- 
pounded rubber  held  in  place  by  a  double  layer  of  canvas.  This  is  called 
the  breaker  strip.  Outside  of  this  comes  the  tread.  The  tread  is  the 
part  that  comes  into  contact  with  the  road  and  takes  the  wear.  This 
whole  structure  is  then  vulcanized  to  make  a  solid  unit. 

The  inner  tube,  which  is  merely  a  rubber  bag  with  a  check  valve 
to  hold  the  air,  is  inserted  in  the  casing  and  the  casing  is  fitted  on  the 


FIG.  24.  FIG.  25. 

FIGS.  24  AND  25. — Types  of  detachable  rims. 

rim  in  such  a  way  that  when  the  pressure  is  applied  the  bead  grips  the 
rim,  and  the  flanges  on  the  rim  prevent  the  tire  from  sliding  off  sideways. 
18.  Rims. — Rims  may  be  classified  as  clincher,  detachable,  and 
demountable,  or  a  combination  of  two  of  these.  The  cuts  shown  in 
Figs.  24,  25,  and  26  show  sections  of  the  Goodyear  rims.  Figure  24 
illustrates  the  detachable  rim  of  two  parts.  The  side  ring  can  be  easily 
removed  from  the  groove  by  a  screw-driver.  The  higher  the  inflation 
pressure  in  the  tire  the  harder  the  side  ring  hugs  the  groove.  This 
rim  is  used  to  a  great  extent  on  electric  pleasure  cars. 


FIG.  26.— Demountable-detachable  rim. 


Figure  25  shows  a  heavier  type  of  detachable  rim,  quite  general 
on  gasoline  pleasure  cars. 

Figure  26  shows  a  rim  which  has  both  the  demountable  and  detach- 
able features  combined.  With  demountable  rims,  an  extra  rim  with 
tire  fully  inflated  may  be  carried.  In  case  of  a  blow-out,  the  damaged 
tire  and  its  rim  may  be  quickly  removed  and  the  spare  rim  and  tire  put 
on.  This  saves  considerable  time  in  cases  of  tire  trouble. 

Figures  27  and  28  show  the  rim  made  by  the  General  Rim  Co.     This 


GENERAL  CONSTRUCTION 


21 


is  a  demountable  rim  and  is  locked  on  the  rim  at  a  single  point.  To 
remove  the  rim  from  the  wheel  the  toggle  nut  is  turned  to  its 
lowest  position  on  the  end  of  the  clamping  bolt,  as  shown  in  Fig.  28. 
This  draws  the  clamping  ring  into  the  groove  and  the  rim  is  re- 
leased and  ready  for  removal.  To  replace  the  rim  merely  reverse  this 
operation. 


Felloe  band 


Felloe 
Demountable  rim 


Toggle  nut 
FIG.  27. 


Felloe   \         \     ^^^^  \ 
Felloe  bane/    \          /  UlP    C/amp 
Demountable  rim     Clomping  boft 
FIG.  28. 


FIGS.  27  AND  28. — Demountable  clincher  rim. 

Figure  29  shows  sections  of  the  clincher  rim  as  used  on  the  Ford 
car,  and  also  shows  the  method  of  removing  the  tire  from  the  rim. 

19.  The  Speedometer  Drive. — Some  device  for  indicating  the  speed 
should  be  installed  on  every  car  as  the  cost  of  one  fine  will  purchase  a 
reliable  speedometer. 


Second  Position 
of  Tire  Tool 


FIG.  29. — Method  of  removing  clincher  tires. 

The  drive  may  be  taken  from  a  gear  attached  to  the  transmission, 
as  shown  in  Fig.  30,  or  from  a  similar  attachment  on  one  of  the  front 
wheels. 

Figure  31  shows  a  speedometer  drive  installed  in  the  spindle  of 
the  steering  knuckle  and  driven  from  a  plate  under  the  hub  cap.  This 
eliminates  the  use  of  an  exposed  gear  and  requires  no  attention  except 
proper  lubrication.  Care  should  be  used  to  see  that  the  drive  plate  is 
properly  replaced  if  the  hub  cap  is  removed  for  any  reason. 


22 


THE  GASOLINE  AUTOMOBILE 


FIG.  30. — Speedometer  drive  from  transmission. 


SPEEDOMETER  GEAR 

SPEEDOMETER  GEAR  BUSHING 
SPEEDOMETER  DRIVE  SH/ 

SPEEDOMETER  DRIVE  PLATE 


H 


SPEEDOMETER  PJNIOM 

OOMETER  PINION  BUSHING 


SPEEC 


SPEEDOMETER  END  CONNECTION 


FIG.  31. — Speedometer  drive  through  knuckle  spindle. 


GENERAL  CONSTRUCTION 


23 


20.  Control  Systems. — Figures  32  and  33  show  the  two  prevailing 
control  systems.  Figure  32  shows  the  left-hand  drive  and  center  con- 
trol system  generally  used  on  cars  with  sliding  gear  transmissions. 


SPARK  CONTROL  LEVE 


IGNITION  SWITC 


SPEEDOMETER 


CLUTCH  PEDAL 

ACCELERATOR  PEDAl 


/  REGULATOR 

SERVICE   BRAKE  PEDAL 


EMERGENCY  BRAKE  LEVER 
^CONTROL  LEVER 


FIG.  32. — Left-hand  drive,  center  control. 


FIG.  33.— The  Ford  control. 

The  operation  is  as  follows:  The  left-hand  pedal  operates  the  clutch 
and  the  other  pedal  the  foot  or  service  brake.  The  right-hand  Jever 
operates  the  emergency  brake.  The  left-hand  lever  operates  the  change 
gears  as  follows:  To  the  left  and  ahead  for  reverse,  to  the  left  and  back 


24  THE  GASOLINE  AUTOMOBILE 

for  low  speed  ahead,  to  the  right  and  ahead  for  second  speed  ahead,  and 
to  the  right  and  back  for  third  or  high  speed  ahead.  This  order  of 
events  is  not  standard  for  all  cars.  Every  car  has  its  own  system  of 
shifting  gears. 

Figure  33  shows  the  Ford  control  system.  This  system  consists  of 
three  foot  pedals  and  one  hand  lever.  The  pedal  on  the  left  operates 
the  clutch  and  controls  the  high  and  low  speed.  The  hand  lever  also 
operates  the  clutch  and  when  drawn  all  the  way  back  sets  the  emergency 
brake.  With  the  hand  lever  forward  and  left  pedal  up  it  is  then  in 
high  gear.  To  get  low  speed  ahead,  the  left  pedal  is  pressed  all  the 
way  forward;  halfway  in  releases  the  clutch?  The  second  or  middle 
pedal  marked  "R"  operates  the  reverse  mechanism.  To  reverse  the 
car  the  hand  lever  must  be  in  a  vertical  position  or  the  clutch  pedal  half- 
way in;  then  pressing  on  the  reverse  pedal  drives  the  car  backward. 
The  right-hand  pedal  operates  the  foot  or  service  brake,  which  is  on 
the  transmission. 

The  chapters  to  follow  will  treat  in  detail  of  the  various  parts  of 
the  car,  their  construction,  methods  of  operation,  and  maintenance. 


CHAPTER  II 
ENGINES 

21.  What   is   an   Explosion? — Practically   all   gasoline   engines   are 
driven  by  explosions  which  take  place  within  the  cylinder  of  the  engine 
and  drive  the  piston,  thus  causing  rotation  of  the  revolving  parts  of  the 
engine.     These  explosions  are  in  a  way  very  similar  to  the  explosions  of 
gunpowder  or  dynamite.     When  a  charge  of  gunpowder  is  fired  in  a 
cannon  or  gun,  the  gunpowder  burns  and  produces  gases  which  exert  a 
tremendous  pressure  on  the  shell  and  force  it  from  the  gun. 

Practically  any  substance  that  will  burn  can  be  exploded  if  under  the 
proper  conditions.  An  explosion  is  merely  a  burning  of  some  material 
taking  place  almost  instantaneously,  so  that  a  great  amount  of  heat  is 
generated  all  at  once.  When  any  substance  burns,  it  unites  rapidly 
with  oxygen  from  the  air.  If  we  want  to  get  an  explosion,  it  is  necessary 
to  have  the  fuel  very  finely  divided  and  carefully  mixed  with  air,  so  that 
the  burning  can  be  very  rapid.  Then,  if  we  start  the  fuel  burning,  by  an 
electric  spark  or  any  other  means,  the  flame  instantly  spreads  throughout 
the  mixture  and  an  explosion  occurs.  In  a  gasoline  engine  we  take  in 
gasoline  vapor  mixed  carefully  with  air.  This  mixture  is  then  exploded 
inside  the  cylinder  of  the  engine.  The  force  of  this  explosion  drives  the 
piston  and  the  motion  is  transmitted  through  the  connecting  rod  to  the 
crank.  To  make  the  process  continuous  and  keep  the  engine  going,  it  is 
necessary  to  get  rid  automatically  of  the  gases  from  the  previous  ex- 
plosion and  to  get  a  fresh  charge  into  the  cylinder  ready  for  the  next 
explosion.  This  process  must  be  carried  out  regularly  by  the  engine,  in 
order  to  keep  it  running. 

22.  Cycles. — As  we  have  just  seen,  an  engine  must  supply  itself  with 
an  explosive  mixture  so  that  the  force  of  the  explosion  will  cause  the 
engine  to  move,  and  it  must  get  rid  of  these  dead  gases  and  get  in  a  fresh 
charge  of  gas  and  air  and  explode  this  so  as  to  keep  up  the  motion. 
There  are  in  use  at  the  present  time  two  principal  systems  of  performing 
this  series  of  operations.     These  systems,  or  rather  the  series  of  opera- 
tions, are  called  cycles,  and  the  engines  are  named  according  to  the 
number  of  strokes  it  takes  to  complete  a  cycle.     These  two  cycles,  or 
systems  of  engines,  are  the  four-stroke  cycle  and  the  two-stroke  cycle. 

Remember  that  a  cycle  refers  to  the  series  of  operations  the  engine 
goes  through.     In  the  four-stroke  cycle  there  are  four  strokes  or  two 
revolutions.     In  the  two-stroke  cycle  there  are  two  strokes  or  one  revolu- 
5  25 


26  THE  GASOLINE  AUTOMOBILE 

tion.  Many  people  leave  out  the  word  stroke  and  talk  of  "four-cycle 
engines"  and  "two-cycle  engines."  This  causes  the  misunderstanding 
that  many  people  have  as  to  just  what  a  cycle  really  is.  A  better  way  is 
to  call  them  "four-stroke. engines"  and  "two-stroke  engines." 

23.  The  Four-stroke  Cycle.— Figures  34,  35,  36  and  37  show  an  engine 
which  operates  according  to  the  four-stroke  cycle.  The  engine  shown 
here  is  a  vertical  engine,  that  is,  the  cylinder  is  placed  above  the  crank 
shaft  (instead  of  being  at  one  side)  and  the  piston  moves  up  and  down 
in  the  cylinder.  This  is  the  prevailing  form  for  automobile  engines. 


SPARK  PLUG 
'INLET  VALVE 


SUCTION    STROKE 

FIG.  34. 


COMPRESSION   STROKE 

FIG.  35. 


Any  engine  consists  of  four  principal  parts:  the  cylinder,  which  is 
stationary  and  in  which  the  explosion  occurs;  the  piston,  which  slides 
within  the  cylinder  and  receives  the  force  of  the  explosion;  the  connecting 
rod,  which  takes  the  force  from  the  piston  and  transmits  it  to  the  crank; 
and  lastly  the  crank,  which  revolves  and  receives  the  force  of  the  explosion 
as  the  piston  goes  in  one  direction,  and  which  then  shoves  the  piston 
back  to  its  starting  point.  A  four-stroke  engine  has  a  number  of  other 
minor  parts,  whose  uses  will  be  brought  out  presently.  This  engine  uses 
four  strokes  of  the  piston  to  complete  the  series  of  operations  from  one 
explosion  to  the  next,  and  is  therefore  said  to  operate  on  the  four-stroke 
cycle,  or  it  is  said  to  be  a  "four-stroke"  engine.  The  first  illustration, 
Fig.  34,  shows  the  engine  just  drawing  in  a  mixture  of  gas  and  air.  This 
is  continued  until  the  piston  gets  clear  down  to  the  bottom  of  the  stroke, 


ENGINES 


27 


and  the  cylinder  is  full  of  this  explosive  mixture.  This  operation  is  called 
the  suction  stroke.  Then  the  valves  are  shut,  as  in  Fig.  35,  and  the  piston 
is  forced  back  to  its  top  position.  This  squeezes  or  compresses  the  gas 
into  a  space  left  in  the  top  of  the  cylinder,  and  this  process  of  compressing 
it  is  called  the  compression  stroke.  After  the  piston  gets  to  the  top,  the 
gases  are  ignited  or  set  fire  to  and  burn  so  quickly  that  an  explosion 
results  and  the  piston  is  driven  down  again,  as  in  Fig.  36.  This  is  called 
the  expansion  or  working  stroke.  When  it  reaches  the  bottom  of  the 
stroke,  another  valve  is  opened,  and  while  the  piston  is  returning  to  the 


WORKING    STROKE 

FIG.  36. 


EXHAUST  STROKE 

FIG.  37. 


top  position  it  forces  out  through  this  valve  the  burned  gases  which  occupy 
the  cylinder  space.  This  is  the  exhaust  stroke.  The  engine  is  now  ready 
to  repeat  this  series  of  operations.  These  operations  have  taken  two 
'revolutions  or  four  strokes.  A  stroke  means  a  motion  of  the  piston 
from  either  end  of  the  cylinder  to  the  other  end.  Consequently,  there 
are  four  strokes  in  the  cycle  of  operations  of  this  engine,  and  we  therefore 
call  it  a  four-stroke  engine. 

24.  The  Order  of  Events  in  Four-stroke  Engines. — The  various  parts 
or  events  in  the  four-stroke  cycle  are  shown  on  the  diagram  of  Fig.  38. 
This  shows  the  two  revolutions  of  the  four -stroke  cycle  divided  up  so  as  to 
show  the  crank  positions  when  the  different  events  occur.  The  diagram 
is  drawn  for  a  vertical  engine  with  the  crank  revolving  to  the  left,  as 
shown  on  the  engine  of  Figs.  34  to  37.  This  is  the  direction  of  rotation 


28  THE  GASOLINE  AUTOMOBILE 

of  an  automobile  engine  to  a  person  in  the  car  looking  forward  toward  the 

^Starting  at  the  top  of  the  diagram,  we  have  just  exploded  the  charge 
and  as  the  crank  swings  over  to  the  left  the  gases  are  expanded.  Before 
the  crank  reaches  the  bottom,  the  exhaust  valve  is  opened.  This  is 
kept  open  while  the  piston  is  returned  to  the  top.  The  inlet  valve  is 
then  opened  and  the  suction  stroke  occurs  as  the  crank  and  piston  again 
descend.  Just  after  the  crank  passes  the  bottom,  the  inlet  valve  closes. 
Both  valves  being  now  closed,  the  charge  is  compressed  as  the  crank  and 
piston  rise  again  to  the  top.  A  short  time  before  reaching  the  top, 
ignition  occurs.  This  should  be  just  far  enough  before  the  top  so  that 
the  explosion  or  combustion  is  taking  place  as  the  crank  passes  the  top 
and  starts  to  descend  on  the  expansion  stroke. 


FIG.  38. — Order   of  events   in  the  four-stroke   cycle. 

25.  The  Mechanism  of  Four-stroke  Engines. — In  addition  to  the  four 
principal  parts  previously  mentioned,  there  are  a  number  of  other  small 
parts  which  we  will  now  discuss.  First,  we  must  have  two  valves  located 
in  the  upper  end  of  the  cylinder,  one  for  the  purpose  of  letting  in  the 
fresh  mixture  of  gas  and  air,  and  the  other  for  the  purpose  of  letting  out 
the  burned  gases.  Each  of  these  valves  opens  once  in  a  cycle,  that  is, 
once  in  two  revolutions.  In  this  engine  (Figs.  34  to  37)  the  valves  are 
shown  in  the  T-head  arrangement,  the  inlet  valve  being  on  the  left  and 
the  exhaust  valve  on  the  right.  These  valves  are  of  a  form  called  poppet 
valves.  They  are  mushroom  shaped,  with  beveled  edges  which  fit  into  a 
beveled  seat.  The  valves  are  held  shut  by  springs  on  the  outside,  which 
pull  on  the  valve  stems  and  hold  them  tightly  against  the  seat,  so  that 


ENGINES  29 

gases  can  not  leak  in  or  out,  except  when  one  of  the  valves  is  opened. 
To  operate  the  valves,  there  are  two  push  rods,  one  for  each  valve. 
These  push  rods  receive  their  motion  from  the  cams.  On  the  lower  ends 
of  these  rods  are  rollers,  and  these  roll  on  cams  on  the  cam  shaft  inside  of 
the  crank  case.  These  cams  have  each  a  hump  or  projection  on  about 
one-fourth  of  their  circumference.  When  one  of  these  strikes  the  roller 
it  raises  it  up,  and  this  motion  is  transmitted  through  the  push  rod  to  the 
valve.  After  the  projection  of  the  cam  has  passed  under  the  roller,  the 
valve  spring  will  close  the  valve  and  force  the  push  rod  back  to  the 
original  position. 

Since  the  valves  on  an  engine  each  work  but  once  in  two  revolu- 
tions, the  engine  must  be  arranged  so  that  the  cams  come  around  only 
once  in  two  revolutions.  To  do  this,  the  general  arrangement  is  to 
put  a  small  gear  on  the  crank  shaft  and  have  this  drive  another  gear, 
twice  as  large,  on  the  cam  shaft.  In  this  way  the  cam  shaft  will  run 
at  just  half  the  speed  of  the  crank  shaft.  These  gears  are  called  half- 
time  gears. 

26.  Valve  Timing  and  Setting. — The  exhaust  valve  of  an  engine  opens 
on  an  average  of  about  45°  before  the  end  of  the  stroke,  in  order  that  the 
pressure  may  be  reduced  to  atmospheric  by  the  end  of  the  stroke  so  there 
will  be  no  back  pressure  during  the  exhaust  stroke.  At  the  end  of  the 
exhaust  stroke,  the  exhaust  valve  should  remain  open  while  the  crank  is 
passing  the  center  so  that  any  pressure  remaining  in  the  cylinder  may  have 
time  to  be  reduced  to  atmospheric. 

The  inlet  valve  very  seldom  opens  before  the  exhaust  closes.  Most 
manufacturers  do  not  open  the  inlet  until  the  exhaust  closes,  for  fear 
of  back-firing,  although  there  is  little  danger  of  this  except  with  slow- 
burning  mixtures.  The  inlet  valve  opens,  on  an  average,  10°  late  (after 
center).  At  the  end  of  the  suction  stroke  there  is  still  a  slight  vacuum 
in  the  cylinder  and  the  inlet  is  kept  open  for  a  few  degrees  past  center  to 
allow  this  to  fill  up  and  get  the  greatest  possible  quantity  of  gas  into  the 
cylinder.  On  an  average,  the  inlet  valve  closes  about  35°  late,  de- 
pending on  the  piston  speed  of  the  engine. 

In  studying  the  valve  setting  of  an  engine,  the  first  step,  of  course,  is 
to  observe  the  timing  of  the  engine  as  it  stands.  To  do  this  we  must  turn 
the  engine  by  hand.  By  inserting  a  thin  sheet  of  tissue  paper  between 
a  valve  stem  and  its  push  rod,  we  can  tell  when  the  valve  opens  and 
closes  by  noticing  when  the  paper  is  gripped  in  opening  the  valve  and 
when  it  is  released  in  closing.  The  corresponding  crank  positions  should 
be  noted.  We  can  then  see  whether  it  is  possible  to  do  anything  to 
improve  the  valve  setting.  Valve  cams  are  made  for  a  certain  valve 
setting  and  will  give  a  certain  angle  of  opening.  This  may  become 
altered  in  several  ways.  Any  excessive  lost  motion  in  the  valve  motion 


30  THE  GASOLINE  AUTOMOBILE 

will  result  in  a  valve's  opening  too  late  and  closing  too  early.  Wear  on 
the  cam  will  have  the  same  effect.  If  a  cam  shaft  has  been  removed  and 
replaced,  the  timing  gears  may  be  put  together  wrong.  This  would  ad- 
vance or  retard  the  whole  series  of  events  and  can  readily  be  found  out 
when  the  timing  is  observed. 

The  clearance  or  lost  motion  in  the  valve  mechanism  between  the 
cam  and  the  valve  stem  should  be  about  3^4  in.  or  less.  In  order  to 
keep  the  valves  quiet  on  their  engines,  some  makers  use  a  clearance  of  the 
thickness  of  ordinary  writing  paper,  or  about  %0oo  in-  If  the  clear- 
ance or  lost  motion  is  too  great,  it  will  cause  the  valve  to  open  late  and 
close  early,  and  will  also  cause  the  cam  to  strike  the  roller  a  hard  blow 
with  the  middle  of  its  face,  instead  of  catching  it  gradually  at  the  beginning 
of  the  incline.  It  will  also  reduce  the  valve  opening  and  possibly  choke 
the  engine. 

In  a  four-stroke  engine  the  cam  shaft  revolves  once  for  each  two 
revolutions  of  the  crank  shaft.  Consequently,  a  valve  opening  of  180° 
will  be  represented  by  but  90°  on  the  cam,  and,  for  any  given  crank 
angle  through  which  the  valve  is  to  be  open,  the  corresponding  cam  angle 
will  be  but  one-half  the  given  crank  angle.  If  an  exhaust  valve  is  to 
open  45°  before  the  beginning  of  the  exhaust  stroke  and  close  10°  after 
the  end  of  the  stroke,  the  total  crank  angle  will  be 

180°  +  45°  +  10°  =  235° 

235° 
The    corresponding    cam    angle  =     ~     =  117^°.     By    "cam    angle" 

we  mean  the  angle  on  the  cam,  from  the  point  where  it  starts  to  open  the 
valve  to  the  point  where  the  valve  is  seated  again.  An  inlet  valve  that 
is  to  open  10°  late  and  close  30°  late,  would  have  a  total  crank  angle  of 

180°  -  10°  +  30°  =  200° 

200° 
The  corresponding  cam  angle  =  — ^—  =  100°. 

27.  Valves. — The  prevailing  type  of  valve  is  what  is  called  the  poppet 
or  mushroom  type — poppet,  from  its  operation,  and  mushroom,  from  its 
shape.  The  exhaust  valve  must  be  opened  by  a  cam  because  it  must 
be  opened  against  a  pressure  of  40  to  60  Ib.  in  the  cylinder  and  held 
open  while  gases  are  forced  out  through  it.  The  inlet  valve  may  be 
opened  by  a  cam  or  we  may  use  a  light  spring  and  depend  on  the  suction 
to  open  it.  The  suction  type  is,  of  course,  cheaper  to  build,  but  it  re- 
duces the  capacity  of  the  engine  so  that  for  the  same  power  there  is  no 
saving.  Consequently  we  find  automatic  inlets  as  a  rule  only  on  the 
small  farm  engines  that  are  built  to  sell  at  a  low  price.  To  open  an 
automatic  valve,  there  must  be  a  difference  in 'pressure  on  the  two  sides 


ENGINES 


31 


of  the  valve  equal  to  the  tension  of  the  valve  spring.  This  tension  may 
be  reduced  or  increased  by  the  weight  of  the  valve,  if  vertical,  and  opening 
respectively  downward  or  upward.  For'  high-speed  engines  an  auto- 
matic valve  is  particularly  unsuited,  since  a  heavy  spring  must  be  used 
to  insure  quick  closing  at  high  speed. 

Poppet  valves  usually  have  45°  beveled  seats  as  shown  in  Fig.  39, 
though  occasionally  flat  valves  are  seen  which  rest  on  flat  seats.  The 
valves  must  be  large  enough  to  let  the  gases  in  and  out  of  the  cylinders 
freely.  If  they  are  too  small  they  will  cut  down  the  power  of  the  engine 
by  not  permitting  it  to  get  a  full  charge.  The  valves  usually  measure 
from  one-third  to  one-half  of  the  cylinder  diameter.  Valve  diameters  are 
usually  measured  by  the  opening  in  the  valve  seat  (see  dimension  marked 
d  in  Fig.  39).  The  diameters  of  the  inlet  and  exhaust  pipes  should  at 
least  equal  this  valve  diameter  and  should  be  larger  if  possible. 


Fia.  39. 


FIG.  40. 


FIG.  41. 


The  valve  lift  should,  when  possible,  be  sufficient  to  give  the  gases  as 
large  a  passage  between  the  valve  and  seat  as  they  have  through  the 
opening  d,  Fig.  39.  For  a  flat  valve  seat  this  would  require  a  lift  of  one- 
fourth  of  the  valve  diameter.  With  a  beveled  seat,  the  gases  pass 
through  an  opening  in  the  shape  of  a  conical  ring  having  a  width  of 
passage  equal  to  hf,  Fig.  39.  To  have  the  necessary  passage  area,  the 
lift  h  of  the  valve  should  be  about  three-tenths  of  the  diameter.  In 
most  stationary  engines  this  lift  can  be  given  the  valve,  but  in  high-speed 
engines  it  would  be  too  noisy.  This  lift  would  then  cause  pounding  and 
wear  on  the  cams;  it  would  require  very  stiff  springs  to  make  the  valves 
follow  the  cams  in  closing  and  would  be  very  hard  on  the  valve  seats  and 
stems.  For  automobile  engines  the  valves  are  made  as  large  as  possible 
and  the  lift  is  limited  to  from  %  Q  to  ^  in. 

The  best  materials  for  valve  heads  are  cast-iron,  nickel-steel,  and 
tungsten-steel.  Cast-iron  is  very  cheap,  easily  worked,  and  stands 
corrosion  well.  It  is  weak,  however,  and  therefore  requires  a  heavier 
weight  than  other  materials  and  this  is  especially  objectionable  for  high- 
speed engines.  The  nickel-steel  is  strong,  non-corrosive,  and  has  a 
very  low  coefficient  of  heat  expansion.  Hence  it  does  not  warp  so  readily 


32 


THE  GASOLINE  AUTOMOBILE 


as  other  metals  It  is  rather  expensive  and  when  used  is  generally 
electrically  welded  to  a  carbon-steel  valve  stem.  The  tungsten-steel  is 
very  hard  and  will  stand  high  temperatures  without  pitting.  Cast-iron 
valve  heads  can  be  screwed  on  a  steel  stem  as  in  Fig.  40,  the  stem  being 
riveted  to  prevent  loosening.  Figure  41  shows  a  common  European  form 


FIG.  42.— T-head. 


FIG.  43.— L-head. 


FIG.  44.— I-head. 


FIG.  45.— L-and-I  head. 


for  valves  which  is  being  rapidly  adopted  here.  The  curvature  under- 
neath gives  the  gases  a  smooth  passage  without  any  of  the  whirling  eddies 
that  occur  under  the  ordinary  flat  valve. 

Any  valve  needs  regrinding  into  its  seat  occasionally  with  oil  and 
emery  or  ground  glass.  Exhaust  valves  require  this  more  often  than 
inlet  valves,  as  they  become  warped  and  pitted  by  the  hot  gases.  After 


ENGINES 


33 


a  valve  is  ground  in,  the  push  rods  should  be  readjusted,  as  the  grinding 
will  lower  the  valve  and  reduce  the  clearance  in  the  valve  motion. 

28.  Valve  Arrangements. — The  possible  arrangements  of  the  valves 
in  the  cylinder  are  numerous.  Figure  42  shows  the  T-head  arrangement 
used  in  many  of  the  large  automobiles.  This  arrangement  permits  of  a 
large  valve  and  a  low  lift,  and  therefore  makes  a  very  quiet  engine.  Fig- 
ure 43  shows  the  L-type  with  both  valves  on  one  side.  This  is  the  most 
common  type.  It  requires  only  one  cam  shaft  and  has  a  very  simple, 


INNER    SLEE 


FIG.  46. — Section  of  Silent  Knight  engine. 

direct-acting  valve  mechanism.  It  does  not  have  as  much  cooling  surface 
to  the  combustion  chamber  and  is,  therefore,  more  economical  in  the  use 
of  fuel  than  the  T-head.  Figure  44  shows  the  valve-in-the-head  arrange- 
ment. This  is  sometimes  called  the  I-head  arrangement.  It  is  especially 
popular  for  racing  cars  because  it  gives  a  short,  quick  passage  into  the 
combustion  chamber  and  gives  a  simple,  compact  combustion  chamber 
with  a  minimum  loss  of  heat  to  the  cooling  water.  Figure  45  shows  an 
arrangement  used  on  the  Reo  car  that  is  a  combination  of  the  L-type 
and  the  valve-in-the-head  type,  the  intake  valve  being  in  the  top  and 


34  THE  GASOLINE  AUTOMOBILE 

operated  by  a  rocker  arm  while  the  exhaust  is  on  the  side  and  is  operated 
by  a  direct  push  rod.     Both  valves  are  operated  from  one  cam  shaft. 

29.  The  Knight  Engine.— The  Knight  engine  is  built  on  the  principle 
of  the  four-stroke  cycle,  but  the  usual  poppet  valves  have  been  replaced 
by  two  concentric  sleeves  sliding  up  and  down  between  the  piston  and 
cylinder  walls.  Certain  slots  in  these  sleeves  register  with  one  another 
at  proper  intervals,  producing  direct  openings  into  the  combustion 
chamber  from  the  exhaust  and  inlet  ports.  The  construction  of  the 
Steams-Knight  motor  is  illustrated  in  Fig.  46  which  shows  the  general 
arrangement  of  the  parts  and  their  nomenclature. 


FIG.  47. — Action  of  sleeves  in  Knight  engine. 


It  will  be  noted  that  two  sleeves  are  independently  operated  by  small 
connecting  rods  working  from  an  eccentric  or  small  crank  shaft  running 
lengthwise  of  the  motor.  This  eccentric  shaft  is  positively  driven  by 
a  silent  chain  at  one-half  the  speed  of  the  crank  shaft.  The  eccentric 
pin  operating  the  inner  sleeve  is  given  a  certain  lead  or  advance  over 
that  operating  the  outer  sleeve.  This  lead,  together  with  the  rota- 
tion of  the  eccentric  shaft  at  half  the  crank-shaft  speed,  produces  the 
valve  action  illustrated  in  Fig.  47,  which  shows  the  relative  positions  of 
the  piston,  sleeves,  and  cylinder  ports  at  various  points  in  the  rotation  of 
the  crank  shaft. 

30.  The  Rotary  Valve.— The  rotary  valve  as  used  in  the  Speedwell 
car  consists  of  two  cylindrical  shafts  in  the  head  of  the  motor,  one  for  ex- 


ENGINES 


35 


haust  and  one  for  the  inlet.  These  shafts  are  slotted  and  when  rotating 
register  with  ports  in  the  cylinder  walls,  thus  opening  passageways  for 
intake  and  exhaust  gases.  The  rotary  movement  of  the  valves  is  con- 
tinuous in  one  direction,  the  valves  being  driven  by  a  silent  chain  from 
the  crank  shaft.  Figure  48  illustrates  the  different  positions  of  the 
rotary  valves  at  the  beginning  of  each  of  the  four  strokes.  The  arrows 
inside  show  the  direction  of  rotation  of  the  valves  and  the  arrows  out- 
side indicate  the  direction  of  the  fresh  gas  going  in  and  the  exhaust  gas 
passing  out  of  the  cylinder. 

31.  Two-stroke  Engines. — Two-stroke  engines  as  a  class  are  not  so 
flexible  as  the  four-stroke  engines  under  the  varying  speeds  and  loads 
encountered  in  automobile  service.  Consequently  they  have  not  been 
used  to  any  great  extent  in  motor  cars,  although  a  few  satisfactory  cars 
have  been  built  with  them. 


INDUCTION 


COMPRESSION  EXPLOSION 

FIG.  48. — Speedwell  rotary  valve  engine. 


EXHAUST 


Since  the  piston  of  a  four-stroke  engine  receives  an  impulse  or  ex- 
plosion only  once  in  two  revolutions,  considerable  effort  has  been  ex- 
pended in  trying  to  develop  an  automobile  engine  that  would  give  an 
explosion  in  each  cylinder  every  revolution  and  yet  would  operate  as 
satisfactorily  and  economically  as  the  four-stroke  engine.  An  impulse 
every  revolution  would  make  a  more  powerful  engine  than  one  of  the 
same  size  which  received  an  impulse  only  once  in  two  revolutions  and  it 
would  also  make  the  flow  of  power  more  continuous  for  the  same  number 
of  cylinders. 

The  Two-port  Engine. — Most  of  the  two-stroke  engines  in  use  are  very 
much  like  those  shown  in  Figs.  49  to  52.  In  appearance,  these  engines 
are  much  simpler  than  the  four-stroke  engine,  but  are  not  necessarily 
any  simpler  in  operation.  They  do  not  have  any  valves  opening  into  the 
combustion  chamber,  such  as  are  found  in  the  four-stroke  engine.  The 
exhaust  gases  leave  the  cylinder  through  a  port  in  the  cylinder  wall,  which 
is  uncovered  by  the  piston  at  the  end  of  the  expansion  stroke,  as  shown  in 
Fig.  50.  At  the  same  time,  a  fresh  charge  is  blown  into  the  cylinder  through 


36  THE  GASOLINE  AUTOMOBILE 

a  similar  port  on  the  other  side.  The  top  of  the  piston  has  a  deflector 
which  turns  the  incoming  charge  up  into  the  clearance  space.  The 
charge  then  strikes  the  cylinder  head,  which  turns  it  down  on  the  other 
side  toward  the  exhaust  port,  thus  driving  the  dead  gases  out  ahead  of 
it.  The  piston  then  comes  back,  shuts  off  both  these  openings  and 
compresses  the  fresh  charge  into  the  clearance  space  as  shown  in  Fig. 
49.  It  is  then  ignited  in  the  usual  manner  by  a  spark  plug  screwed  into 
the  cylinder  head.  This  gives  the  piston  an  impulse  every  revolution. 

The  engines  of  Figs.  49  to  52  have  each  crank  enclosed  all  around 
and  they  use  this  case  or  chamber  as  a  sort  of  a  pump  to  supply  fresh  gas 
to  the  cylinder.  When  the  piston  goes  up,  the  space  inside  the  crank  case 
is  increased,  and  when  it  comes  down  the  space  is  reduced,  thus  main- 
taining a  breathing  action  inside  the  crank  case.  In  Fig.  49  the  piston 


Spark  Plug 


Exhaust  Port 
Transfer  Port 
/  Check  Valve  (Open)  jig 
Carburetor 


/Deflector 
Transfer 

Check    Valve  (Closed) 


FIG.  49.  FIG.  50 

FIGS.  49  AND  50. — Two-port,  two-stroke  engine. 

is  shown  traveling  toward  the  top.  This  motion  causes  a  suction  in 
the  crank  case  and  causes  air  to  enter  through  the  carburetor.  As  the 
air  passes  through  the  carburetor  it  becomes  saturated  with  gasoline  and 
then  passes  through  the  check  valve  into  the  crank  case.  When  the 
piston  gets  to  the  top,  the  suction  ceases  and  the  check  valve  is  closed 
by  its  spring.  Meanwhile,  an  explosive  mixture  has  been  compressed 
above  the  piston  and  at  the  top  of  the  stroke  is  ignited  by  a  spark.  This 
produces  an  explosion  or  rise  in  pressure  above  the  piston,  just  as  in  the 
four-stroke  cycle  and  this  drives  the  piston  down  on  its  working  stroke. 
As  the  piston  comes  down,  it  compresses  the  fresh  gases  in  the  crank 
case  into  a  smaller  volume  and  thus  raises  their  pressure.  Meanwhile, 
as  the  piston  nears  the  bottom  of  its  stroke,  it  uncovers  the  exhaust  port 
and  the  pressure  in  the  cylinder  causes  a  large  part  of  the  burned  gases 


ENGINES 


37 


to  shoot  out  through  this  port.  An  instant  later  the  piston  uncovers  a 
transfer  port  on  the  other  side  and  is  now  in  the  position  shown  in  Fig. 
50.  This  transfer  port  is  connected  into  the  crank  case  and  therefore  allows 
the  gases  from  the  crank  case  to  blow  over  into  the  cylinder  as  shown 
in  Fig.  50. 

The  piston  head  is  so  shaped  as  to  form  a  deflector,  which  turns 
the  fresh  charge  toward  the  cylinder  head  so  that  it  can  not  blow  out 
the  exhaust  port.  The  piston  then  returns,  cuts  off  these  ports,  and 
compresses  this  charge,  meanwhile  drawing  another  charge  into  the 
crank  case.  This  engine  is  called  a  two-port  type,  because  there  are  only 
two  ports  in  the  cylinder  walls  to  be  operated  by  the  piston. 

The  Three-port  Engine. — The  only  difference  between  this  type  and 
the  preceding  one  is  in  the  method  of  admitting  the  gases  into  the  crank 


Spark  Plug 


Met  Port 


Deflector 
•Transfer  Port 


Exhaust 


Carburetor  \-, 


FIG.  51.  FIG.  52. 

FIGS.  51  AND  52. — Three-port,  two-stroke  engine. 

case.  Instead  of  using  a  check-valve,  the  admission  of  the  gases'  to  the 
crank  case  is  controlled  by  the  piston,  which  uncovers  a  third  port  in  the 
cylinder  walls  as  it  nears  the  top  of  the  compression  stroke.  As  will  be 
seen  in  Fig.  51,  the  carburetor  is  on  the  other  side  of  the  engine,  placed 
just  below  the  exhaust  pipe.  As  the  piston  rises,  it  creates  a  suction  in 
the  crank  case,  but  there  is  no  way  for  any  gas  to  get  in  until  the  piston 
reaches  the  top  of  its  stroke.  As  the  piston  uncovers  this  third  port,  the 
air  enters  with  a  rush  through  the  carburetor,  picks  up  the  gasoline  on  its 
way  through,  and  enters  the  crank  case.  The  piston  then  descends,  cuts 
off  the  third  port,  compresses  the  gases  in  the  crank  case,  as  in  Fig.  52, 
and  then  blows  them  over  into  the  cylinder  as  before. 

Against  the  two-stroke  engine  we  have  the  facts  found  from  ex- 
perience that  they  'are  not  as  economical  in  the  use  of  fuel  and  are  more 


38  THE  GASOLINE  AUTOMOBILE 

uncertain  in  their  action  than  the  four-stroke  engine.  Since  the  fresh 
charge  is  depended  on  to  blow  out  the  exhaust  gases,  it  is  evident  that 
some  of  the  incoming  charge  is  liable  to  pass  out  through  the  exhaust  port. 
Gases  mix  very  quickly  and  it  is  not  possible  to  keep  the  dead  and  fresh 
gases  separate,  and  yet  drive  the  dead  gases  out  and  fill  the  cylinder  com- 
pletely with  fresh  gases.  If  a  full  charge  enters  through  the  transfer 
port,  some  of  it  will  be  lost  through  the  exhaust  port  without  its  being 
utilized.  By  skillfully  proportioning  the  two  ports  and  the  shape  of  the 
deflector  to  the  size  and  speed  of  the  engine,  it  is  possible  to  largely  pre- 
vent the  waste  of  fuel  through  the  exhaust  port. 

A  two-stroke  engine  does  not  get  as  full  a  charge  of  gas  as  does  a  four- 
stroke  engine  and,  consequently,  will  not  be  twice  as  powerful.  The 
horse  power  of  a  two-stroke  engine  is  usually  about  1%  to  1^  times  that 
of  a  four-stroke  engine  of  the  same  size  and  speed. 

The  small  two-stroke  engines  shown  in  Figs.  49  to  52  sometimes  cause 
trouble  from  back-firing  or  exploding  in  the  crank  case.  This  is  caused 
by  the  mixture  in  the  crank  case  becoming  ignited  and  exploding  before 
it  goes  over  into  the  cylinder.  This  wastes  the  energy  of  the  gas  and  fills 
the  crank  case  with  dead  gases,  so  that  the  engine  will  frequently  come  to 
a  stop.  Back-firing  is  caused  by  the  mixture  in  the  cylinder  being  still  in 
flames  when  the  piston  uncovers  the  transfer  port.  The  flame  shoots 
through  this  port  into  the  crank  case  and  fires  the  mixture  there.  It  has 
been  found  by  experience  that  mixtures  weak  in  gas  are  the  ones  which 
burn  slowly  and  therefore  cause  back-firing.  Consequently,  the  cure  for 
crank-case  explosions  is  to  give  the  engine  more  fuel. 

Any  leaks  into  the  crank  case  are  very  serious  in  either  of  these 
types.  With  the  slow  speed  used  -in  starting  an  engine  by  hand,  a  very 
small  leak  may  admit  air  enough  to  satisfy  the  suction  in  the  crank  case 
and  thus  prevent  any  gas  from  being  drawn  in  or,  at  any  rate,  it  may  so 
weaken  the  mixture  as  to  make  it  non-explosive. 

This  brief  statement  of  some  of  the  difficulties  of  the  two-stroke  engine 
will  show  some  of  the  things  that  must  be  overcome  in  order  to  make  this 
type  of  motor  generally  applicable  to  automobile  service. 

32.  The  Flywheel. — The  purpose  of  the  flywheel  is  to  keep  the  engine 
running  from  one  explosion  to  the  next,  and  to  make  the  engine  run 
smoothly.  If  an  engine  did  not  have  a  flywheel,  it  would  run  in  a  very 
jerky  manner,  if  it  ran  at  all,  and  it  is  more  probable  that  the  explosion 
would  simply  drive  the  piston  to  the  other  end  of  the  stroke  and  that  it 
would  stop  there.  Any  one  knows  that  the  heavier  a  moving  object  is 
and  the  faster  it  is  going,  the  harder  it  is  to  stop  it.  The  flywheel  on  an 
engine  is  quite  heavy  and  the  result  is  that,  once  started,  it  will  keep  the 
engine  going  for  some  time.  A  gas-engine  flywheel  must  not  only  be 
heavy  enough  to  keep  it  going  from  one  explosion  to  the  next,  but  must 


ENGINES  39 

keep  it  going  without  allowing  the  speed  of  the  engine  to  drop  down  too 
much  between  explosions. 

33.  Ignition. — In  order  to  cause  the  explosions  within  the  cylinder, 
some  means  must  be  provided  for  lighting  the  charge  of  gas.     This  is 
usually  done  by  causing  an  electric  spark  to  pass  between  two  points 
within  the  cylinder.     The  spark  sets  fire  to  the  mixture  and  the  explosion 
follows. 

There  are  two  general  methods  of  electric  ignition.  One  of  these  is 
called  the  make-and-break  system  because  it  requires  some  moving 
parts  inside  the  cylinder  to  make  an  electric  circuit,  and  then  break  it 
quickly  so  that  a  spark  will  occur  inside  the  cylinder.  The  other  system 
is  called  the  jump-spark  system.  This  is  the  system  used  in  automo- 
biles. There  are  no  moving  parts  which  have  to  pass  through  the  cylinder 
wall  in  this  system.  The  spark  coil  or  magneto  makes  a  current  powerful 
enough  to  jump  between  two  fixed  points  inside  the  cylinder.  The 
complete  details  of  these  systems  of  ignition  will  be  taken  up  in  a  later 
chapter. 

34.  Clearance  and  Compression. — It  was  discovered  by  some  of  the 
early  inventors  of  gas  engines  that  compressing  a  gaseous  mixture  causes 
it  to  give  a  much  more  powerful  explosion.     Consequently,  all  gas  engines 
draw  in  a  full  cylinder  charge  of  gas  and  air,  and  then  compress  this  back 
into  a  space  left  at  the  upper  or  rear  end  of  the  cylinder.     This  space, 
which  is  left  for  the  gas  to  occupy  when  the  piston  is  at  the  top  end  of  its 
stroke,  is  called  the  clearance  space  or  combustion  chamber.     The  amount 
of  this  clearance  space  in  relation  to  the  whole  cylinder  volume  determines 
just  how  much  the  gas  is  compressed.     It  has  been  found  from  experience 
that  different  kinds  of  gases  require  different  amounts  of  compression  and, 
therefore,  the  clearance  space  is  made  different  for  different  fuels.     The 
clearance  is  generally  spoken  of  as  being  a  certain  per  cent,  of  the  piston 
displacement,  varying  from  24  to  30  per  cent,  for  automobile  engines. 

35.  Piston  Displacement. — This  refers  to  the  space  swept  through  by 
the  piston  in  going  from  one  end  of  the  stroke  to  the  other.     It  is  given 
this  name  because,  as  the  piston  moves  through  its  stroke,  it  will  either 
draw  in  or  force  out  that  volume  of  air  or  gas.     The  piston  displacement 
is  calculated  by  multiplying  the  length  of  stroke  by  the  area  of  a  circle 
whose  diameter  is  the  inside  diameter  of  the  cylinder.     For  example,  a 
3j^-in  by  5-in.  engine  (this  means  33^  in.  inside  cylinder  diameter  and 
5  in.  stroke)  would  have  a  piston  displacement  as  follows: 

The  area  of  a  3^-in.  circle  is  0.7854  X  3>^  X  3>£  =  9.621  sq.  in. 

The  piston  displacement  is  5  times  this,  or  48.105  cu.  in. 

The  clearance  of  such  an  engine  would  be  from  24  to  30  per  cent, 
of  this.  If  we  suppose  that  it  is  25  per  cent.,  then  the  actual  space  which 
must  be  left  for  the  clearance  will  be  48.105  X  0.25  =  12.026  cu.  in. 


40  THE  GASOLINE  AUTOMOBILE 

36.  Cylinder  Cooling.— When  an  explosion  occurs  inside  the  cylinder 
of  an  engine,  the  gases  on  the  inside  reach  a  temperature  somewhere 
around  3000°.     The  walls  of  the  cylinder  are,  of  course,  exposed  to  this 
high  heat  and  would  very  quickly  get  red  hot  if  we  did  not  have  some  way 
of  keeping  them  cool.     The  polished  surface  upon  which  the  piston  slides 
would  be  very  quickly  spoiled.     The  most  common  way  of  keeping  the 
cylinder  cool  is  by  the  use  of  water,  and  the  arrangement  for  this  is  shown 
in  the  engines  illustrated  in  this  chapter.     Surrounding  the  cylinder  is  a 
jacket  with  a  space  between  for  the  cooling  water.     By  keeping  a  supply 
of  water  passing  through  this  space,  the  cylinder  can  be  kept  cool  enough 
for  the  operation  of  the  engine.     The  cylinder  head  is  also  cast  with  a 
double  wall,  especially  around  the  valves,  so  that  these  parts  will  also  be 
kept  cool.     The  cooling  fluid  used  is  generally  water,  although  sometimes 
special  anti-freezing  solutions  are  used  where  there  is  danger  of  the 
engine  freezing.     Water  should  not  be  allowed  to  remain  in  the  jacket  of 
an  engine  over  night  if  there  is  danger  of  a  frost,  as  the  freezing  of  the 
water  will  crack  the  cylinder.     When  the  supply  of  water  is  limited,  as 
in  an  automobile,  the  water  is  cooled  in  a  radiator  or  system  of  pipes,  and 
used  over  again.     The  water  is  kept  in  circulation  by  a  pump  or  by  the 
thermo-syphon  system  and  the  hot  water  is  cooled  by  the  air  passing  over 
the  radiator. 

37.  The  Muffler. — When  the  exhaust  valve  of  an  engine  opens  at  the 
end  of  the  expansion  stroke  the  pressure  of  the  gas  inside  the  cylinder  is 


FIG.  53.— Typical  muffler. 

still  about  50  or  60  Ib.  per  square  inch.  The  valve  must  open  and  let 
this  pressure  out  before  the  piston  starts  back,  or  else  the  back  pressure 
will  tend  to  stop  the  engine.  The  valve  is  opened  quickly,  and  the  high 
pressure,  being  suddenly  released  into  the  exhaust  pipe,  causes  the 
sharp  sound  which  we  hear  when  an  engine  exhausts.  This  sound  is  not 
the  sound  of  the  explosion,  as  is  commonly  supposed.  The  real  ex- 
plosion takes  place  a  little  before  this  sound  and  can  be  heard  only  as  a 
dull  thump  inside  the  cylinder.  The  explosion  occurs  at  the  beginning 
of  the  working  stroke,  while  the  sound  that  we  hear  in  the  exhaust  comes 
at  the  end  of  the  stroke. 

In  order  to  prevent  this  sudden  exhaust  from  causing  too  great  a 


ENGINES  41 

noise  it  is  customary  to  have  a  muffler.  A  muffler  is  generally  a  chamber 
in  the  exhaust  pipe  which  receives  the  exhaust  gases  from  the  engine  and 
expands  them  gradually  into  the  outside  air,  thus  preventing  a  loud 
noise.  A  common  arrangement  of  an  automobile  muffler  is  shown  in 
Fig.  53. 

38.  Horse  Power  of  Engines. — The  horse  power  of  an  engine  is 
the  measure  of  the  rate  at  which  it  can  do  work.  One  horse  power  is 
a  rate  of  33,000  ft.-lb.  a  minute.  There  are  two  ways  of  measuring 
engine  power.  We  can  determine  the  power  developed  by  the  ex- 
plosions in  the  cylinder,  in  which  case  we  have  what  is  called  the  indi- 
cated horse  power  (i.hp.} ;  or  we  can  attach  a  brake  to  the  flywheel  and 
measure  the  power  which  the  engine  actually  delivers.  This  is  called 
the  brake  horse  power  (b.hp.).  Engines  are  usually  rated  by  their  brake 
horse  power  because  that  is  what  they  are  actually  capable  of  delivering. 
The  brake  horse  power  of  an  automobile  engine  will  usually  be  from  70 
to  85  per  cent,  of  its  indicated  horse  power,  the  loss  being  that  consumed 
in  the  engine  mechanism. 

There  are  a  number  of  quick  rules  for  estimating  the  power  of  engines 
according  to  their  cylinder  dimensions  and  the  speed.  Those  most 
used  for  four-stroke  engines  are  given  below.  The  simplest  of  these  and 
the  one  most  used  is  known  as  the  S.  A.  E.  formula  or  Society  of  Auto- 
mobile Engineers  formula. 

Authority  Formula 

S.  A.  E.  1  D2N 

=  hp. 


Royal  Auto  Club  2.5 

Brit.  Inst.  of  Auto  Engrs.     0.45  (D  +  L)  (D  -  1.18)  =  hp. 

D27  7?  AT 
E.  W.  Roberts  --         =  hp. 


D  =  diameter  of  cylinder  in  inches.       R  =  revolutions  per  minute  of 

crank  shaft. 
L  =  length  of  stroke  in  inches.  N  =  number  of  cylinders. 

Derivation  of  the  S.  A.  E.  Horse  Power  Formula.  —  The  indicated  horse 
power  of  a  single-cylinder,  four-stroke  engine  is  equal  to  the  mean  ef- 
fective pressure,  P,  acting  throughout  the  working  stroke,  times  the  area 
of  the  piston,  A,  in  square  inches,  times  one-quarter  times  the  piston  speed, 
S,  divided  by  33,000,  thus: 

PAS 
~  33,000  X  4 

Multiplying  this  by  the  number  of  cylinders,  N,  gives  the  indicated 
horse  power  for  an  engine  of  the  given  number  of  cylinders,  and  further 
multiplying  by  the  mechanical  efficiency  of  the  engine,  E,  gives  the 
brake  horse  power. 

6 


42  THE  GASOLINE  AUTOMOBILE 

Therefore,  the  complete  equation  for  brake  horse  power  reads: 

PASNE 
b.hp.  -  33^000  x  4 

The  S.  A.  E.  formula  assumes  that  all  motor  car  engines  would  de- 
liver or  should  deliver  their  rated  power  at  a  piston  speed  of  1000  ft. 
per  minute,  that  the  mean  effective  pressure  in  such  engine  cylinders 
would  average  90  Ib.  per  square  inch,  and  that  the  mechanical  efficiency 
would  average  75  per  cent. 

Substituting  these  values  in  the  above  brake  horse  power  equation, 
and  substituting  for  A  its  equivalent,  0.7854Z)2,  the  equation  reads: 

90  X  0.7854P2  X  1000  X  N  X  0.75 
33,000  X  4 

and  combining  the  numerical  values  it  reduces  to: 


To  make  it  simpler,  the  denominator  has  been  changed  to  2.5  without 
materially  changing  the  results. 

The  formula  can  be  simplified,  however,  for  ordinary  use  by  consider- 
ing the  number  of  cylinders;  thus  for  the  usual  four-,  six-,  and  eight- 
cylinder  engines  it  becomes: 

1.6  D2  =  hp.  for  all  four-cylinder  motors. 

2.4  D2  =  hp.  for  all  six-cylinder  motors. 

3.2  D2  =  hp.  for  all  eight-cylinder  motors. 

4.8  D2  =  hp.  for  all  twelve-cylinder  motors. 

The  S.  A.  E.  formula  comes  very  close  to  the  actual  horse  power 
delivered  by  most  automobile  engines  at  the  piston  speed  of  1000  ft. 
per  minute.  However,  at  the  present  time,  most  of  the  engines  will 
deliver  the  maximum  power  at  speeds  higher  than  this,  usually  around 
1500  ft.  per  minute.  As  a  result,  the  power  which  the  engines  are  capable 
of  delivering  is  greater  than  that  given  by  the  S.  A.  E.  formula.  The 
formula  will  serve,  however,  as  a  means  of  comparing  engines  on  a  uniform 
basis. 


CHAPTER  III 

POWER-PLANT  GROUPS  AND  TRANSMISSION  SYSTEMS 

39.  Single-  and  Multi-cylinder  Engines. — The  first  automobile  power 
plant  consisted  of  a  one-cylinder  engine  which  gave  power  impulses  at 
regular  intervals  of  time  for  the  propulsion  of  the  car.  Naturally  it 
operated  very  jerkily  and  with  considerable  noise,  due  to  the  size  of  the 
cylinder  and  the  time  between  impulses.  These  facts  led  to  the  adoption 


-Two  Revolutions- 


Compreaalon 


1  Cylinder 


2  Cylinders 


4  Cylinders 


6  Cylinders 


8  Cylinders 


FIG.  54. — Power  diagrams. 

of  the  two-,  four-,  and  six-cylinder  engines,  and  quite  recently  the  eight-  and 
twelve-cylinder  engines  have  come  into  use  as  automobile  power  plants. 
In  Fig.  54  can  be  seen  one  of  the  distinct  advantages  of  the  multi- 
cylinder  engine  for  motor  car  purposes.     The  length  of  the  diagram 
represents  two  revolutions  of  the  engine  crank  shaft.     The  curved  line 
7  43 


44  THE  GASOLINE  AUTOMOBILE 

acefg  represents  the  variations  in  the  power  from  a  single  cylinder.  The 
line  bh  represents  uniform  power  requirement  of  the  car.  When  the 
power  curve  goes  above  bh  the  engine  accelerates  and  the  surplus  power 
is  thus  stored  in  the  flywheel;  when  the  curve  goes  below  bh  the  flywheel 
gives  up  power  and  the  engine  slows  down. 

As  the  number  of  cylinders  increases,  the  impulses  increase  in  fre- 
quency, the  average  power  is  greater,  and  above  four  cylinders  there  is 
no  period  during  which  some  cylinder  is  not  delivering  power.  This 
means  that  in  a  six-  or  eight-cylinder  car,  there  is  no  time  at  which  the 
flywheel  must  supply  all  the  power  required  by  the  car. 

The  multi-cylinder  engine,  therefore,  furnishes  a  practically  continu- 
ous flow  of  power  to  the  car  with  little  vibration.  The  increase  in  the 
number  of  cylinders  has  a  tendency  to  reduce  the  size  of  each  cylinder 
and  this  fact  combined  with  the  steady  operation  of  the  engine,  makes  the 
modern  automobile  engine  a  very  smooth-running,  quiet,  power-plant 
unit. 

40.  Power  Plant  and  Transmission  Arrangements. — Figure  55  shows 
the  arrangement  of  the  Studebaker  power  plant  and  transmission  system. 
The  engine  is  placed  in  the  front  of  the  frame,  being  supported  at  four 
points.  The  clutch,  which  is  of  the  cone  type,  is  built  inside  the  flywheel, 
and  permits  the  engine  to  be  disengaged  from  the  transmission  system. 
The  propeller  shaft,  which  transmits  the  power  from  the  engine  to  rear 
wheels,  is  connected  to  the  clutch  by  means  of  a  universal  joint  which 
permits  the  shaft  to  receive  power  and  to  deliver  it  to  the  rear  axle. 

The  change-gear  set  or  transmission  is  placed  on  the  rear  axle  just  in 
front  of  the  differential  housing  which  carries  the  differential  gear.  The 
change-gear  set  permits  the  relative  speed  of  the  engine  and  car  to  be 
changed  according  to  conditions.  The  chassis  diagram  indicates  the 
location  of  the  other  important  parts.  Notice  the  three-quarter  elliptic 
rear  springs. 

The  chassis  of  the  Mitchell  "Eight"  is  shown  in  Fig.  56.  The  engine 
in  this  case  is  supported  at  only  three  points,  one  at  the  front  and  two  at 
the  rear.  The  clutch  is  of  the  cone  type  operating  in  connection  with  the 
flywheel.  It  will  also  be  noticed  that  the  change-gear  set  is  placed  at  the 
front  of  the  propeller  shaft,  which  then  goes  directly  to  the  final  drive 
on  the  rear  axle.  There  is  a  single  universal  joint,  which  is  between  the 
clutch  and  gear  set. 

The  Hollier  " Eight"  chassis  is  shown  in  Fig.  57.  Here  we  see  the 
application  of  the  well-known  "unit  power  plant"  in  which  engine, 
clutch,  and  change  gears  are  built  into  one  single  unit.  This  arrangement 
permits  the  use  of  only  one  universal  joint  between  power  plant  and  rear 
axle.  Notice  the  cantilever  type  of  rear  springs. 

In  the  chassis  of  the  Ford  Model  T,  Fig.  58,  use  is  also  made  of  the 


POWER-PLANT  GROUPS 


45 


~~Un/  verso/ 
,'    Joints 


FIG.  55.— Chassis  of  Studebaker  "Six, 


46 


THE  GASOLINE  AUTOMOBILE 


FIG,  56,— Chassis  of  Mitchell  "Eight 


POWER-PLANT  GROUPS 


47 


Un/f 


FIG.  57.— Chassis  of  Hollier  "Eight." 


4g  THE  GASOLINE  AUTOMOBILE 

"unit  power  plant"  with  three-point  support.  The  engine,  clutch,  and 
change  gears  are  built  together  in  a  single  unit  and  are  supported  on  the 
frame  at  only  three  points.  The  connection  between  power  plant 
and  rear  axle  is  made  by  the  use  of  only  one  universal  joint.  As  will  be 
seen  later,  this  car  is  equipped  with  a  "planetary"  transmission  which  is 
built  on  a  principle  entirely  different  from  the  usual  clutches  and  change- 
gear  sets.  The  entire  rear  of  the  car  is  supported  by  an  inverted  semi- 


Tic.  58.— Chassis  of  Ford  Model  T. 

elliptic   spring  extending   over  the   rear   axle.     A   similar   but  lighter 
spring  is  used  in  front. 

The  sectional  view  of  the  Lyons-Knight  four-cylinder  car  in  Fig.  59 
shows  very  clearly  the  arrangement  of  the  engine  and  the  transmission 
groups.  The  engine  is  of  the  Knight  type  and  delivers  its  power  through 
a  plate  clutch  and  through  the  universal  joints  and  propeller  shaft  to  the 


POWER-PLANT  GROUPS 


49 


50 


THE  GASOLINE  AUTOMOBILE 


change  gear  set  built  on  the  rear  axle.  The  final  drive  from  shaft  to  axle 
is  of  the  worm  type  which  will  be  discussed  later  in  the  chapter.  The 
clutch  control  pedal  and  the  change  gear  control  lever  are  outlined  very 
clearly. 

41.  Modern  Automobile  Power  Plants.  —  The  automobile  power  plant 
includes  the  engine  and  all  accessories  necessary  for  the  production  of 
power.  The  transmission  system  includes  the  mechanism  necessary  for 
taking  this  power  furnished  by  the  power  plant  and  transmitting  it  to  the 
rear  wheels. 

In  most  cases,  the  power  plant  includes  the  engine  and  its  component 
parts  such  as  carburetor,  ignition  devices,  cooling  system,  etc.  and  the 


Hot    water  outlet-,^ 


Air  heater 


exhaust 
Co/a1  water 


Cone  -~ 
c/utch 


'ater  supply 
to  pump 

Water  pump 
Magneto 


FIG.  60. — Four-cylinder  Wisconsin  engine. 

transmission  system  includes  the  clutch,  change  gears,  universal  joints, 
differential,  and  rear  axle.  When  the  unit  power  plant  is  used,  it  includes 
in  addition  to  the  engine  and  its  essential  component  parts,  the  clutch  and 
the  change  gears. 

Four-cylinder  Power  PZante.— Figure  60    illustrates  a  typical  four- 
cylinder  automobile  engine  with  the  essential  parts  indicated.     The  view 
shown  is  the  exhaust  side  of  the  motor,  it  having  the  T-head  valve  arrange- 
ment.   The  cylinders  are  cast  in  pairs,  two  cylinders  being  in  each  unit, 
he  water  jackets  are  cast  integral  with  the  cylinders.     The  water  con- 
itions  at  the  top  and  bottom  of  each  casting  are  indicated.     The  clutch, 


POWER-PLANT  GROUPS 


51 


•Sfar~f/'n(j  motot — generator- 


FIG.  61.— The  1914  Cadillac  engine. 


52 


THE  GASOLINE  AUTOMOBILE 


FIG.  62. — Studebaker    "Four"  engine. 


FIG.  63.— Section  of  Buda  engine. 


POWER-PLANT  GROUPS 


III  1 1 


54 


THE  GASOLINE  AUTOMOBILE 


one  member  of  which  is  machined  in  the  engine  flywheel,  is  of  the  cone 
type,  this  being  the  customary  method  of  applying  the  cone  clutch  to  the 
engine. 


The  engine  of  the  1914  Cadillac  is  illustrated  from  both  sides  in  Fig.  61 
s  of  the  L-head  type,  having  both  intake  and  exhaust  manifolds  on 


POWER-PLANT  GROUPS  55 

the  right  side.  The  most  prominent  feature  of  this  engine  is  that  the 
cylinders  are  cast  singly  with  copper  water  jackets  fastened  securely 
around  the  castings.  The  single-cylinder  castings  necessitate  a  longer 
engine  than  if  cast  in  pairs  or  en  bloc,  but  they  also  make  the  renewal 
expense  less  if  a  single  cylinder  is  damaged. 

Figure  62  is  a  right-side  view  of  the  Studebaker  "Four"  engine, 
showing  the  en  bloc  cylinder  construction,  in  which  all  cylinders  are  cast 
in  one  piece.  This  permits  the  engine  to  be  much  shorter  than  when 
cast  in  any  other  way.  The  structure  is  also  more  rigid,  and  can  be 
made  considerably  lighter  than  when  cast  singly. 


wafer  oaf/ef 
Removable,   cylinder  \ 

head       \  ft  j.      •     connection 


one  clutch  Cy/inc/ers  cast  en- bloc 


FIG.  66.— Power  plant  of  MitcheU  "Six." 

The  sectional  view  of  a  Buda  Model  T  engine  in  Fig.  63  shows  very 
clearly  the  internal  construction  of  an  engine.  This  engine  is  of  the 
L-head  type  with  only  one  cam  shaft.  The  crank  shaft  is  of  the  con- 
ventional three-bearing  type,  i.e.,  with  a  bearing  at  each  end  and  one 
at  the  center. 

The  Ford  unit  power  plant  is  shown  in  section  in  Fig.  64  with  all 
parts  fully  designated.  The  magneto,  change  gears  and  clutching  ar- 
rangement are  of  considerable  interest  and  will  be  discussed  under  the 
proper  headings.  As  will  be  remembered,  this  power  plant  has  three- 
point  support. 


56 


THE  GASOLINE  AUTOMOBILE 


Six-cylinder  Power  Plants. — The  Jeffrey  six-cylinder  power  plant 
is  shown  in  section  in  Fig.  65.  The  cylinders  are  cast  in  pairs,  thus 
permitting  the  use  of  a  four-bearing  crank  shaft.  In  the  pair  of  cylinders 
at  the  left,  the  section  is  taken  through  the  valves  so  as  to  show  the  cams, 
push  rods,  springs,  and  valves.  The  center  pair  is  sectioned  through 
the  center  of  the  cylinders  so  as  to  show  the  pistons,  pins,  and  con- 
necting rods.  The  valve  arrangement  is  of  the  L-head  type. 

The  engine  of  the  "Mitchell  Six  of  '16,"  Fig.  66,  has  the  six  cylinders 
cast  "en  bloc,"  which  gives  a  very  compact  and  rigid  construction  of 
pleasing  appearance.  The  cylinder  head  can  be  removed  in  one  piece  for 
the  purpose  of  cylinder  and  valve  examination. 

The  Franklin  motor,  Fig.  67,  represents  a  very  interesting  and 
unique  design,  having  overhead  valves  and  air-cooling.  The  cylinders 
are  cast  singly  and  each  is  air  cooled  by  a  system  of  cast  ribs  and  air 
cooling,  doing  away  with  the  water  jackets  around  the  cylinders.  The 


FIG.  67.— The  Franklin  air-cooled  engine. 

air  is  drawn  downward  around  the  cylinder  ribs  by  the  suction  of  the 
flywheel  fan. 

42.  Constructional  Features  of  Four-  and  Six-cylinder  Engines.— The 
essential  differences  of  construction  in  the  various  four-  and  six-cylinder 
engines,  outside  of  the  methods  of  cylinder  construction  and  valve  arrange- 
ment, consist  in  the  construction  and  arrangement  of  the  cam  and  crank 
shafts.  Figure  68  is  a  conventional  four-cylinder  crank  shaft,  shown  with 
connecting  rods  and  pistons  attached.  There  are  three  main  bearings, 
as  indicated.  The  connecting  rod  bearings  are  all  in  the  same  plane,  bear- 
ings Nos.  1  and  4  being  just  180°  from  Nos.  2  and  3.  This  means  that 
the  Nos.  1  and  4  pistons  are  in  the  same  position  in  the  cylinders  at  the 
same  time.  Likewise  Nos.  2  and  3  are  in  the  same  position.  If  No.  1 
piston  is  on  the  compression  stroke,  No.  4  must  necessarily  be  on  the 
exhaust  stroke  and  Nos.  2  and  3  on  the  suction  and  explosion  strokes, 


POWER-PLANT  GROUPS 


57 


The  order  of  firing  in  a  four-cylinder  engine  must  be  in  the  order  1,  3, 
4,  2  or  1,  2,  4,  3. 

The  five-bearing  crank  shaft  for  a  four-cylinder  engine  has  main  bear- 
ings between  all  the  cranks.    Figure  69  shows  the  five-bearing  crank  shaft 


FIG.  68. — Three-bearing,  four-cylinder  crank  shaft. 

in  place  on  the  1914  Cadillac  four-cylinder  engine.  This  type  of  crank- 
shaft construction  is  especially  adapted  to  an  engine  with  individually 
cast  cylinders. 


Chain  drive  for- 


ajneto  &  oump 


FIG.  69. — Five-bearing,  four-cylinder  crank  shaft  in  position. 

The  crank  shaft  for  a  six-cylinder  engine  is  arranged  as  shown  in  Fig. 
70.     Cranks  1  and  6,  2  and  5,  3  and  4  are  in  pairs  and  are  spaced  120° 


58 


THE  GASOLINE  AUTOMOBILE 


apart.  The  pistons  in  the  paired  cylinders  are  always  in  the  same  relative 
positions  in  the  cylinders.  The  firing  order  of  the  cylinders  is  usually  1, 
5,  3,  6,  2,  4  or  1,  2,  3,  6,  5,4.  This  crank  has  four  main  bearings.  The 


PISTON  RINS 
PISTON 


XNn  SHAFT  SEAR'NS 

CONNECTING  WOO  BEARHMS 
•OH-  DIPPER 

CRANK  SHAFT 

CRANK 
SHAFT  GBA« 

/          'STARTINS 
INUT 


FIG.  70. — Four-bearing,  six-cylinder  crank  shaft. 

shaft  shown  in  Fig.  71  has  only  three  main  bearings.     The  arrangement 
of  the  cranks  is  the  same  as  in  the  previous  case. 


Matn   bearings 


FIG.  71.— Three-bearing,  six-cylinder  crank  shaft. 

In  Figs.  72  and  73  are  illustrated  the  two  general  methods  of  cam  shaft 
construction.     Figure  72  is  a  one-piece  cam  shaft,  the  cams  and  shaft 


Fia.  72. — One-piece  cam  shaft. 

being  made  of  one  solid  bar  of  steel.  This  is  the  more  common  method  of 
construction.  The  assembled  cam  shaft,  Fig.  73,  on  which  the  individual 
cams  are  pinned  or  keyed  is  used  at  present  in  very  few  cases.  The  ob- 


POWER-PLANT  GROUPS 


59 


jection  to  this  type  of  shaft  is  that  the  cams  may  become  loose  on  the 
shaft  and  give  considerable  trouble.  For  an  L-head  engine,  a  single  cam 
shaft  on  one  side  of  the  engine  carries  both  inlet  and  exhaust  cams.  For 


FIG.  73.— Assembled  cam  shaft. 


FIG.  74. — Cadillac  eight-cylinder  V-type  engine. 

a  T-head  engine,  however,  one  cam  shaft  carries  the  inlet  cams  on  one  side 
of  the  engine  and  another  shaft  carries  the  exhaust  cams  on  the  other  side 


60  THE  GASOLINE  AUTOMOBILE 

The  cam  shafts  are  driven  at  one-half  crank  shaft  speed.  The  drive 
can  either  be  by  a  silent  chain,  such  as  shown  for  the  1914  Cadillac  in  Fig. 
69,  by  spur  gears  such  as  in  the  Ford  Model  T  shown  in  Fig.  64,  or  by 
helical  gears  such  as  shown  in  Figs.  72  and  73. 

43.  Eight-  and  Twelve-cylinder  Power  Plants. — In  the  four-cylinder 
engine,  there  is  a  power  stroke  every  one-half  revolution,  but  during  a 
small  interval  at  the  end  of  each  power  stroke  no  power  is  being  delivered 
by  the  engine.  This  means  short  periods  in  the  operation  of  the  engine  in 
which  the  flywheel  must  supply  all  the  power.  In  the  six-cylinder  engine, 


FIG.  75. — Sectional  view  of  Cadillac  eight-cylinder  engine. 


there  is  a  power  stroke  every  one-third  revolution  and,  as  a  result,  there  is 
an  overlapping  and  a  more  continuous  flow  of  power  (see  Fig.  54).  The 
impulses  come  oftener  and,  consequently,  reduce  the  vibration.  The 
same  effect  is  carried  further  in  the  eight-cylinder  engine  which  gives  a 
power  stroke  every  one-fourth  revolution.  The  parts  are  considerably 
lighter  and  this  aids  in  reducing  the  vibration.  Most  of  the  eight-cylinder 
engines  are  built  in  the  V-type  and  this  method  of  construction  adds  to  the 
smoothness  of  operation. 

Cadillac  Eight-cylinder  Engine.— Figure  74  is  a  front-end  view  of  the 
Cadillac  eight-cylinder  engine.     The  cylinders  are  arranged  in  blocks  of 


POWER-PLANT  GROUPS 


61 


four  each,  placed  in  a  V-shape  at  an  angle  of  90°.  A  cross  section  of  two 
opposite  cylinders  is  shown  in  Fig.  75.  The  engine  is  of  the  L-head  type 
with  the  valves  on  the  inside  of  the  V.  One  cam  shaft  placed  directly 
above  the  crank  shaft  operates  all  of  the  sixteen  valves  by  means  of  the 
rockers  as  shown.  Eight  cams  serve  to  operate  the  sixteen  valves,  as 


FIG.  76. — A  pair  of  Cadillac  connecting  rods. 


FIG.  77. 

one  cam  operates  a  valve  in  each  group.     The  cam  shaft  is  carried  by  five 
bearings  and  has  a  silent  chain  drive  as  shown  in  Fig.  74. 

The  crank  shaft  is  like  a  conventional  four-cylinder  shaft  with  three 
main  bearings.  There  are  only  four  crank  pins,  two  connecting  rods,  one 
from  each  group,  bearing  on  the  same  crank.  One  of  the  rods,  Fig.  76, 
is  forked,  while  the  other  is  perfectly  straight,  fitting  in  between  the  fork. 
The  split  bearing  shown  at  the  right  fits  directly  over  the  pin.  The  forked 


62 


THE  GASOLINE  AUTOMOBILE 


rod  fits  over  this  bearing  and  is  pinned  to  it,  so  that  the  rod  and  bearing 
work  together.    The  other  rod  fits  in  the  center  surface  of  the  bearing  and 


LJ 


FIG.  78.— Top  view  of  Mitchell  "Eight"  engine. 


FIG.  79. — Front  view  of  Mitchell  "Eight"  engine. 

runs  on  it.     The  arrangements  permit  the  length  of  the  crank  shaft  to  be 
no  greater  than  in  a  four-cylinder  engine. 


POWER-PLANT  GROUPS 


63 


The  order  of  firing  of  the  eight  cylinders  alternates  from  one  side  to 
the  other.  If  the  cylinders  be  numbered  as  shown  in  Fig.  77  the  firing 
order  is  as  follows:  1-L,  2-R,  3-L,  1-R,  4-L,  3-R,  2-L,  and  4-R.  The  horse 
power  rating  of  the  Cadillac  Eight  is  31.25  according  to  the  S.  A.  E. 
formula.  On  dynamometer  test,  however,  it  has  developed  70  hp.  at  a 
speed  of  2400  r.p.m. 

Mitchell  Eight. — The  Mitchell  Eight  is  constructed  on  the  same  gen- 
eral principle  as  the  type  previously  mentioned.  The  cylinder  groups  are 
placed  in  a  V  of  90°.  The  valves  are  placed  on  the  inside  of  the  V  and 


FIG.  80.— Engine  of  Packard  "Twin  Six." 

are  operated  by  means  of  eight  cams  on  a  single  cam  shaft  mounted  above 
the  crank  shaft.  The  cylinders  are  slightly  staggered  and  two  connecting 
rods  are  mounted  side  by  side  on  each  crank  instead  of  using  the  forked 
construction. 

The  engine  is  rated  at  48  hp.  The  cylinders  are  3-in.  bore  by  5^- 
in.  stroke.  The  top  and  front-end  views  are  shown  in  Figs.  78  and  79. 

The  Packard  Twelve-cylinder  Engine. — The  twelve-cylinder  unit  power 
plant  of  the  Packard  car  is  shown  in  Fig.  80.  The  twelve  cylinders  are 
cast  in  two  blocks  of  six,  arranged  in  V-type  with  an  included  angle  of  60°. 
The  cylinders  have  a  3-in.  bore  and  a  5-in.  stroke  with  L-head  valve  ar- 
rangement. The  left  block  of  cylinders  is  set  forward  of  the  right  set  by 


64 


THE  GASOLINE  AUTOMOBILE 


\Y±  in.  in  order  to  permit  the  lower  end  of  the  connecting  rods  of  opposite 
cylinders  to  be  placed  side  by  side  on  the  same  crank  pin.  In  addition, 
this  arrangement  permits  the  use  of  a  separate  cam  for  each  valve, 
making  24  cams  on  the  cam  shaft.  The  single  cam  shaft  is  placed  directly 
above  the  crank  shaft.  The  crank  shaft  is  of  the  usual  six-cylinder  type 
supported  by  three  main  bearings. 

Advantages  Claimed  for  Eight-  and  Twelve-cylinder  Motors.—  The  chief 
advantages  claimed  by  the  eight-  and  twelve-cylinder  motors  are  smooth 
running,  lack  of  vibration,  rapidity  of  pick-up,  and  wide  range  of  activity 


Flywheel 

Clutch   teathej 

Clutch    cone 

Clutch  release 
r/ny  — — - — \ 

Transmission     \ 
cose- 


Clutch  qear--*\ 
^ 


Clutch  brake 

Clufch  thrust  bearing- 

C/ufch    spring 

Crank  shaft-- 


FIG.  81. — Buick  cone  clutch. 

on  high  gear.  It  is  possible  with  either  of  these  types  to  run  almost 
entirely  on  high  speed  under  all  conditions. 

44.  Clutches. — The  gasoline  engine  must  be  set  in  motion  before  it 
will  take  up  its  cycle  and  generate  power.  This  fact  prevents  it  from  being 
started  under  load  and,  consequently,  means  must  be  provided  for  de- 
taching the  engine  from  the  rest  of  the  mechanism  for  starting  before  the 
load  is  thrown  on.  This  mechanism  for  detaching  the  engine  from  the 
remaining  part  of  the  power  and  transmission  system  is  called  the 
"clutch."  There  are  in  use  at  the  present  time  two  general  types  of 
clutches,  the  cone  type  and  the  disc  type. 

The  Cone  Clutch. — Figure  81  illustrates  the  cone  clutch  as  used  in  the 
Buick  car.  It  consists  of  a  leather-faced  aluminum  cone  which  is  held 


POWER-PLANT  GROUPS  65 

tightly  against  the  inside  of  the  tapered  rim  of  the  flywheel  by  four  springs 
carried  on  a  spider.  The  aluminum  cone  is  mounted  on  a  steel  sleeve 
which  can  slide  back  and  forth  on  the  clutch  gear  shaft  to  disengage  or 
engage  the  cone  with  the  flywheel.  A  grooved  ring  at  the  rear  end  of  the 
sleeve  connects  the  clutch  to  the  clutch  pedal.  A  small  brake,  attached 
to  the  transmission  case,  serves  to  keep  the  clutch  from  spinning  after  it 
is  released.  Four  small  spring  plungers,  located  under  the  leather,  force 
it  out  at  these  points  and  prevent  grabbing  when  the  clutch  is  let  in. 

In  operation,  pressure  on  the  clutch  pedal  is  transmitted  by  a  con- 
necting link  and  clutch  release  shaft  to  the  yoke  operating  on  the  ball- 
bearing release  ring,  which  pulls  the  clutch  back  out  of  engagement  with 
the  flywheel.  The  small  brake  now  holds  the  clutch  stationary,  while 
the  clutch  spider  and  springs  continue  to  turn  with  the  flywheel  until  the 
clutch  is  again  engaged.  When  in  full  engagement,  the  clutch  and  fly- 
wheel turn  as  a  unit,  transmitting  the  power  through  the  gear  set  to  the 
rear  axle. 

Multiple  Disc  Clutches. — The  multiple  disc  clutch  is  built  in  two  types 
— the  dry  plate  and  wet  plate.  Figure  82  is  a  sectional  view  of  the  dry 
plate  type  of  clutch  as  used  on  the  Hudson.  It  consists  of  a  series  of 
alternate  driving  and  driven  discs.  The  driving  discs  receive  their  power 
from  the  flywheel  by  four  studs,  one  of  which  shows  in  the  cut.  These 
discs  are  steel  stampings. 

The  driven  discs  are  also  steel  stampings  but  are  somewhat  thicker 
and  have  holes  into  which  cork  inserts  are  pressed.  The  driven  discs 
drive  the  inner  drum  by  means  of  a  series  of  grooves  or  slots. 

The  driven  and  driving  discs  are  pressed  together  by  the  clutch  spring 
shown.  When  it  is  desired  to  release  the  clutch,  the  foot  pedal  compresses 
the  clutch  spring  and  the  plates  separate,  permitting  the  driving  members 
to  run  independently  of  the  driven  members.  As  -in  all  clutches,  the 
power  is  transmitted  entirely  through  a  frictional  contact.  The  cork 
inserts  are  used  because  they  are  soft  and  at  the  same  time  have  a  great 
adhesive  property,  even  if  they  become  soaked  with  oil.  The  advantage 
of  this  type  of  clutching  arrangement  is  that  a  large  frictional  surface  can 
be  obtained  with  a  comparatively  small  clutch  diameter.  In  the  cone 
type  this  diameter  must  necessarily  be  large  in  order  to  get  the  necessary 
friction  surface  on  the  one  surface  in  contact.  In  letting  in  the  plain  cone 
type  of  clutch,  there  is  also  the  possibility  of  a  more  sudden  engagement 
than  with  the  multiple  disc  type.  This  has  been  overcome  by  the  use  of 
the  springs  under  the  leather,  as  shown  in  Fig.  81. 

The  wet  plate  clutch  is  constructed  on  the  same  general  principles  as 
the  dry  plate  clutch,  the  essential  difference  being  that  it  runs  in  a  bath  of 
oil.  When  the  clutch  is  released,  an  oil  film  covers  the  entire  surface  of 
the  plates  and,  when  the  clutch  is  thrown  in,  this  film  of  oil  is  gradually 


66  THE  GASOLINE  AUTOMOBILE 

squeezed  out,  permitting  a  very  easy  and  gradual  engagement.  In  the 
winter  time,  the  oil  may  be  unusually  heavy  and  this  prevents  a  quick 
engagement.  This  can  be  overcome  by  thinning  the  clutch  oil  with 
kerosene. 


FIG.  82. — Hudson  dry  plate  clutch. 

45.  Change  Gear  Sets. — The  change  gear  set  is  for  the  purpose  of 
permitting  different  speed  ratios  between  the  engine  and  the  car.  When 
starting,  the  engine  must  run  comparatively  fast  and  the  car  slow. 
When  the  car  gets  under  way,  the  relative  speed  of  car  and  engine  must  be 
changed  in  order  to  get  efficient  operation. 

Figure  83  is  the  gear  set  used  on  the  Jeffrey  car.  The  right  shaft  is 
driven  by  the  clutch;  attached  to  this  shaft  is  the  drive  gear  which  at 
all  time  drives  the  lay-shaft  drive  gear  fastened  to  the  lay-shaft.  The  lay 
shaft  in  addition  carries  four  fixed  gears  as  shown.  The  main  drive 
shaft  has  one  end  bearing  rotating  within  the  main  drive  gear.  Con- 
sequently the  drive  gear  and  main  shaft  can  run  independently  of  each 
other.  The  main  shaft  carries  two  sets  of  sliding  gears,  the  names  and 
purposes  of  which  are  indicated.  These  two  sets  are  operated  by  two 


POWER-PLANT  GROUPS 


67 


shifter  yokes  which  lead  to  the  gear  control  lever  in  the  car.  This  gear 
set  provides  four  forward  speeds  and  a  reverse  speed.  This  type  is 
known  as  the  "selective  sliding  gear  set,"  because,  as  the  name  in- 
dicates, any  one  of  the  speeds  can  be  selected  at  will,  in  contrast  to  the 
"progressive  sliding  gear  set"  in  which  the  speeds  must  be  taken  in 
succession. 

Figure  84  illustrates  the  gear  positions  for  the  various  speeds  obtained 
in  the  Studebaker  three-speed-and-reverse  gear  set.  The  white  arrows 
indicate  the  gears  through  which  the  power  is  transmitted  for  the  different 
speeds. 


SHIFTS  R  BOO  C»P  f  ROOT 

IDtNGGCAR  )** 


FIG.  83. — Jeffrey  gear  set. 

46.  Planetary  Gearing. — This  type  of  combined  clutch  and  change 
gears,  such  as  used  on  the  Ford  Model  T,  is  especially  adapted  to  light 
cars  in  which  two  forward  speeds  are  sufficient.  The  gears  are  not  shifted 
into  or  out  of  mesh  for  the  different  speeds,  as  in  the  sliding  gear  set,  but 
they  are  always  in  mesh,  as  shown  in  Fig.  85.  On  high  gear,  the  entire 
mechanism  is  clamped  solidly  together  by  the  clutch  and  revolves  as  a 
single  mass  with  the  flywheel.  The  clutch  is  of  the  multiple  disc  type, 
running  in  oil.  The  flywheel  has  three  studs,  each  of  which  carries  three 
gears  of  different  sizes  fastened  together  to  form  what  is  called  a  "triple 
gear."  These  triple  gears  mesh  with  three  gears  of  different  sizes  in  line 
with  the  engine  shaft.  The  inner  one,  next  to  the  flywheel  face,  is  fast- 


68 


THE  GASOLINE  AUTOMOBILE 


TE 


'       REVERSE   IDLER  GEAR  L" 


'"---PINION    SHAFT    C 


FIRST  SPEED 
OR"  LOW" 


OR  INTERMEDIATE 


THIRD  OR 
"HIGH"  SPEED 


REVERSE 


FIG.  84. — Positions   of   gears   in   Studebaker   three-speed-and-reverse   gear   set. 


POWER-PLANT  GROUPS 


69 


ened  to  the  drive  shaft  which  delivers  the  power  through  to  the  rear  axle. 
The  other  two  central  gears  float  on  the  drive  shaft  and  are  connected 
to  the  two  drums  nearest  to  the  engine.  Surrounding  these  drums,  but 
not  shown  in  the  figure,  are  brake  bands  which  can  be  tightened  by  foot 
pedals.  These  can  be  seen  in  Fig.  64.  If  the  slow-speed  drum  is  gripped, 
the  second  of  the  three  central  gears  will  be  held  stationary.  This  makes 
the  triple  gears  rotate  on  their  studs  as  the  flywheel  revolves.  In  doing 
this,  they  drive  the  inner  central  gear,  or  the  driving  gear,  slowly  forward, 


FIG.  85. — Ford  planetary  transmission. 

due  to  the  differences  in  the  sizes  of  the  gears.  If  the  middle  drum  is 
gripped  instead,  by  pushing  on  the  reverse  pedal,  the  larger  of  the  central 
gears  is  held.  This  makes  the  triple  gears  revolve  again  on  their  studs  as 
the  flywheel  revolves,  but  since  this  reverse  gear  is  larger  than  the  drive 
gear,  the  motion  of  these  triple  gears  will  turn  the  drive  gear  slowly  back- 
ward. For  high  speed,  the  entire  mechanism  is  gripped  solidly  together 
so  that  it  revolves  at  engine  speed.  The  third  drum  is  used  for  a  service 
brake. 

47.  Universal  Joints  and  Drive  Shaft. — The  use  of  one  or  more  univer- 
sal joints  between  the  power  plant  and  the  rear  axle  is  necessary,  as  can 
be  seen  in  Fig.  59,  in  order  to  provide  for  the  lower  position  of  the  rear 
axle  and  also  to  allow  for  the  spring  action  between  the  axle  and  the  frame 
which  carries  the  power  plant.  The  universal  joint  permits  this  to  be 
done  with  very  little  loss  of  power.  Figure  86  shows  the  propeller  shaft 
or  drive  shaft  of  the  Jeffrey  car  with  its  universal  joints.  A  square  block 
in  the  center  of  the  universal  joint  fits  between  the  jaws  of  two  forks,  one 
of  which  is  connected  to  the  power  plant  and  the  other  is  attached  to  the 


70 


THE  GASOLINE  AUTOMOBILE 


end  of  the  drive  shaft.  The  flexible  connection  of  these  forks  to  the  block 
permits  the  drive  shaft  to  oscillate  freely  with  the  rear  axle  and  yet  con- 
tinue to  receive  and  transmit  power. 


ftANOE  YOKE 


COMPLETE  UNIVERSAL  JOINT 


LOCIT  RIN8  D 

FIG.  86. — Jeffrey  propeller  shaft  and  universal  joints. 

48.  Final  Drive. — The  final  drive  to  the  rear  axle  is  accomplished  by 
means  of  bevel,  spiral-bevel,  or  worm  gearing.  The  direction  of  the  power 
transmission  must  be  changed  through  a  right  angle  at  this  point. 
Figure  87  shows  the  bevel  gear  final  drive  as  used  on  the  Jeffrey  car.  Both 
the  bevel  pinion  and  the  differential  housing  which  carries  the  driving  gear 
or  ring  gear  are  carried  by  ball  bearings.  The  action  of  the  bevel  gears 


FIG.  87.— Jeffrey  final  drive. 

produces  a  side  thrust,  caused  by  the  inclination  of  the  faces  of  the  teeth, 
tending  to  separate  the  gears.  This  makes  it  necessary  that  the  bearings 
of  these  gears  be  capable  of  resisting  this  thrust.  Either  ball  bearings  or 
tapered  roller  bearings  are  employed.  If  the  straight  rollers  are  used  for 
bearings,  special  thrust  bearings  must  be  provided. 

"Figure  88  shows  a  spiral-bevel  gear  drive  with  the  Timken  tapered 


POWER-PLANT  GROUPS 


71 


roller  bearings,  as  used  on  the  Cadillac  car.  The  chief  claims  for  the 
spiral-bevel  drive  are  that  the  spiral  teeth  give  a  more  continuous  driving 
action  between  the  teeth  and  overcome  any  possible  inaccuracies  in  the 
teeth  or  any  tendencies  to  wear  irregularly;  also  that  they  overcome  the 
thrust,  to  a  more  or  less  extent,  by  producing  a  counteracting  pull. 

Fig.  89  shows  the  worm  drive  to  the  rear  axle.     This  has  the  worm 
placed  above  the  gear.     The  worm  drive  in  Fig.  59  shows  one  with  the 

worm  placed  underneath.  The  worm 
drive  is  very  quiet  running,  but  requires 
careful  lubrication  because  of  the  con- 
stant sliding  action  between  the  teeth  of 
the  worm  and  gear.  One  of  the  two 
gears  should  run  in  an  oil  bath.  The 
worm  drive  is  especially  popular  in 


FIG.  88.— Cadillac  spiral-bevel 
drive. 


FIG.  89. — Worm  drive  used  on  Jeffrey 
"Chesterfield  Six." 


heavy  truck  service  where  there  is  a  large  reduction  in  speed.  The 
worm  is  generally  made  of  steel  and  the  gear  of  bronze  to  keep  down  the 
friction. 

49.  Types  of  Live  Rear  Axles. — The  dead  rear  axle  was  illustrated  and 
explained  in  Chap.  I.  The  live  axle  is  used  on  practically  all  makes  of 
pleasure  cars,  with  only  one  or  two  exceptions.  Live  rear  axles  are  clas- 
sified according  to  their  methods  of  construction  as  simple,  semi-floating, 
three-quarter  floating,  and  full  floating. 

Simple  Live  Axle. — The  simple  live  axle  used  on  the  Ford  Model  T  is 
shown  in  Fig.  90.  This  type  of  rear  axle  performs  two  functions  in  that 
it  carries  the  entire  weight  of  the  rear  of  the  car  in  addition  to  transmitting 
the  power.  The  rear  wheel  is  keyed  to  the  axle  as  shown.  The  weight 


72 


THE  GASOLINE  AUTOMOBILE 


is  carried  by  roller  bearings  directly  on  the  live  axles  both  at  the  wheel  and 
differential  ends. 

Semi- floating  Axle. — Figure  91  is  of  the  semi-floating  type  and  shows 


ICJOiif 

the  essential  difference  between  a  simple  and  semi-floating  live  axle.     In 

the  semi-floating  axle  the  inner  bearings  are  carried  on  an  extension  of  the 

Qtial.case,  thus  relieving  this  end  of  the  live  axle  of  considerable 


POWER-PLANT  GROUPS  73 

stress.  The  wheel  as  in  the  other  case  is  keyed  to  the  axle.  The  con- 
struction at  the  outer  end  of  the  semi-floating  axle  is  the  same  as  in  the 
simple  axle.  In  either  of  these  types  the  weight  of  the  car  produces  a 
bending  stress  in  the  axle. 

Three-quarter  Floating  Axle. — Figure  92  shows  the  change  in  this  type 
of  construction  from  the  semi-floating  type.  The  weight  is  carried  by  the 
bearings  on  the  housing  and  directly  in  line  with  the  spokes,  thus  re- 
lieving the  axle  of  all  bearing  stresses.  The  wheel  is  keyed  onto  the  shaft. 


FIG.  91. — Semi-floating  rear  axle. 

Although  in  the  three-quarter  type  the  live  axle  is  relieved  of  all  weight, 
nevertheless  the  bending  strains  due  to  a  possible  side  movement  of  the 
wheel,  or  the  distortion  due  to  a  bent  housing  are  still  thrown  on  the  axle 
due  to  the  fact  that  the  wheel  is  keyed  onto  the  axle.  Also,  in  this  type, 
if  the  live  axle  breaks,  the  wheel  can  come  off  and  let  the  car  drop.  This 
is  prevented  only  by  the  full-floating  construction. 

Full-floating  Rear  Axles. — Figure  93  shows  the  full-floating  construc- 
tion as  used  on  the  Buick  car.  The  wheel  is  carried  on  a  double  ball  or 
roller  bearing  on  the  axle  housing,  in  such  a  way  as  to  retain  the  wheel 
on  the  housing  regardless  of  what  may  happen  to  the  live  axle.  In  this 
construction,  the  live  shaft  receives  only  the  torsional  strains  of  driving 
the  car,  all  other  loads  being  taken  by  the  axle  housing.  The  live  shaft 
may  be  removed  and  replaced  without  disturbing  either  the  wheel  or  the 


74 


THE  GASOLINE  AUTOMOBILE 


differential.  The  inner  ends  of  the  axle  shafts  are  grooved  and  slide  into 
corresponding  grooves  in  the  differential  gears.  The  entire  drive  shaft 
on  either  side  may  be  removed  by  merely  removing  a  hub  cap  and  sliding 
the  shaft  out.  In  the  form  shown  in  Fig.  93,  the  shaft  is  keyed  into  the 


FIG.  92. — Three-quarter  floating  axle  construction. 


GIVING    YOKE 


ADJUSTM£MJ 


-  PROPELLER  SHAFT  HOUSING 
BRACE  fiODS 
PROPELLER  SHAFT 


SRAKC.  OPERATING 
SHAFTS 

BRAKE  DRUM         """ 


CREASE  PLUC 


DRIVtMC  FLANGE 
HUB  BEAR/NO 


FIG.  93.— Buick  full-floating  rear  axle. 

hub  cap.  In  another  form,  the  outer  end  of  the  shaft  has  a  toothed  clutch 
which  fits  into  corresponding  recesses  in  the  outer  face  of  the  hub.  This 
permits  a  certain  amount  of  play  and  relieves  the  shaft  from  any  distor- 
tion if  the  axle  housing  becomes  bent. 


CHAPTER  IV 
FUELS  AND  CARBURETT1NG  SYSTEMS 

One  of  the  most  important  operations  in  a  gas  engine  is  that  of  getting 
an  explosive  mixture  inside  of  the  engine  cylinder  at  the  proper  time.  This 
explosive  mixture  is  formed  by  the  thorough  mixing  of  air  and  a  gas 
formed  by  the  evaporation  of  a  volatile  liquid  fuel,  usually  gasoline. 

50.  Hydrocarbon   Oils. — Most   of    the   liquid   fuels  are   known   as 
"hydrocarbon"  oils,  because  they  are  made  from  crude  mineral  oil  con- 
taining as  its  principal  parts,  hydrogen  and  carbon.     One  of  the  hydro- 
carbon fuels,  viz.,  alcohol,  is  not  of  mineral  derivation,  but  is  made  by 
the  distillation  of  vegetable  matter. 

The  crude  oil  or  petroleum  from  which  the  hydrocarbon  fuels  are 
made  is  found  in  natural  deposits  several  hundred  feet  below  the  earth's 
surface.  In  some  places  it  has  to  be  pumped  out,  while  in  others  it  is 
forced  out  by  natural  gas  pressure.  Most  of  the  crude  oil  found  in  the 
United  States  comes  from  Pennsylvania,  Ohio,  Illinois,  Kansas,  Texas, 
Oklahoma  and  California.  These  crude  oils  are  of  two  general  types, 
that  coming  from  Texas,  Oklahoma,  and  California  having  what  is  known 
as  an  "asphalt"  base,  and  that  from  Pennsylvania  and  Ohio  having  a 
"paraffin"  base.  Crude  oil  having  an  "asphalt"  base  is  a  heavy  dark 
liquid,  which  when  boiled,  leaves  a  black  tarry  residue.  If  the  crude  oil 
has  a  "paraffin"  base,  it  is  much  lighter  in  weight  and  color  and,  when 
boiled,  leaves  a  residue  from  which  is  made  the  white  paraffin  or  wax  with 
which  everyone  is  familiar. 

Formerly,  gasoline  made  from  crude  oil  with  a  paraffin  base  was  sup- 
posed to  be  of  a  higher  grade  than  the  other,  but  with  the  modern  proc- 
esses of  refining,  the  gasoline  from  the  two  kinds  of  crude  oil  gives  equally 
good  results. 

51.  Fractional  Distillation  of  Petroleum. — The  crude  oil  is  heated  in 
large  retorts  or  "stills,"  provided  with  accurate  temperature  recording 
devices.     When  the  temperature  has  reached  about  100°F.  a  vapor  be- 
gins to  rise  from  the  oil.     This  vapor  is  collected  from  the  top  of  the  retort 
and  condensed  in  cooling  coils,  from  which  the  liquid  is  collected  in  vessels. 
As  the  temperature  in  the  retort  rises,  the  vapor  becomes  heavier  and, 
when  condensed,  gives  the  heavier  and  less  volatile  liquid  fuels.     The 
following  table  gives,  approximately,  the  products  of  this  method  of 
distillation : 

75 


76  THE  GASOLINE  AUTOMOBILE 

Distilling  at   IOO°F  to   I25°F 
Hiqhly  Volatile  oils  -qasoline, 
benzine,   naphtha,  ICTtolB%. 


Distilling  at    125*  F  to  350*F. 
Kerosene  and   light  lubricat- 
ing oils;  65   to 


Distilling  at  over   35O'F 
Heavy    oils,    paraffin  wax, 
etc,    15  to  20% 


FIG.  94. — Approximate  fractions  in  the  distillation  of  crude  oil. 


Temperature   in   the 
retort 


Kind  of  oil  after  condensing  the  vapor 


Percentage 


100°F  to  125°F. 

125°F.  to  350°F. 
Over  350°F. 

Highly  volatile  oils  (gasoline,  benzine  and 
naphtha). 
Kerosene  and  light  lubricating  oils. 
Heavy  oils,  paraffin  wax  and  residue. 

10  to  15  per  cent. 

65  to  75  per  cent. 
15  to  20  per  cent. 

It  will  be  noticed  that  there  is  from  three  to  five  times  as  much  kerosene 
and  light  lubricating  oils  produced  under  this  method  as  there  is  gasoline. 
This  accounts  for  the  late  scarcity  of  gasoline  and  the  more  volatile  fuels, 
and  the  overproduction  of  kerosene  and  the  less  volatile  fuels,  which  can 
not  be  used  successfully  in  an  automobile  engine. 

In  order  to  utilize  a  part  of  these  less  volatile  fuels,  the  Standard  Oil 
Co.  has  developed  the  Burton  process  by  which  these  less  volatile  fuels 
are  redistilled  under  pressure.  This  process  gives  an  additional  amount 
of  volatile  fuel  very  much  like  the  gasoline  obtained  from  the  first  distilla- 
tion. This  process  has  increased  the  percentage  of  gasoline  from  the 
crude  oil  to  such  an  extent  that  the  market  is  now  liberally  supplied. 

The  Bureau  of  Mines  has  recently  developed  the  new  Rittman  process 
for  increasing  the  amount  of  gasoline  produced  from  the  crude  oil.  It 
is  a  continuous  process,  in  contrast  to  the  "batch"  Burton  process.  The 
two  processes  are  somewhat  similar  in  character  and  have  as  their  end  an 
increase  in  the  production  of  gasoline  from  the  crude  oil. 

62.  Principles  of  Vaporization. — Before  an  explosive  mixture  can  be 
formed,  the  liquid  fuel  must  first  be  turned  into  a  gas  and  then  mixed 
with  the  proper  amount  of  air  to  burn  it.  As  we  know,  it  requires  heat  to 


FUELS  AND  CARBURETTING  SYSTEMS  77 

change  water  into  steam  or  vapor.  If  the  water  is  out  in  the  open,  it  will 
evaporate  rapidly,  or  boil,  at  a  temperature  of  212°.  Likewise,  in  order 
to  change  a  liquid  fuel  into  a  gas  or  vapor,  it  is  necessary  that  heat  be 
added  to  it,  but  the  temperature  at  which  this  heat  is  added  is  different  for 
different  fuels.  For  instance,  gasoline  will  evaporate  under  the  usual 
atmospheric  pressure  and  temperature  and  will,  in  some  cases,  evaporate 
at  a  temperature  close  to  0°  F.  This  can  be  tested  by  exposing  a  pan 
of  gasoline  to  the  air.  In  a  short  time  the  liquid  will  have  evaporated. 
That  heat  has  been  absorbed  can  be  verified  by  feeling  of  the  dish  before 
it  is  filled  and  again  after  evaporation  has  been  taking  place. 

Kerosene  and  alcohol,  on  the  other  hand,  will  not  evaporate  until  heat 
is  added  from  an  external  source  at  a  higher  temperature,  the  same  as  is 
done  when  steam  is  made  from  water.  This  explains  the  difficulty  of 
evaporating  these  fuels  for  use  in  a  gas  engine. 

From  the  above  considerations,  the  general  principles  of  vaporization 
are  formulated : 

1.  The  heavier  a  liquid  and  the  higher  its  boiling  point,  the  harder 
it  will  vaporize;  for  example,  kerosene  as  compared  with  gasoline. 

2.  A  liquid  fuel  will  vaporize  easier  and  faster  under  a  suction,  or  re- 
duction of  pressure  than  under  pressure ;  for  example,  gasoline  is  more  dif- 
ficult to  vaporize  at  low  than  at  high  altitudes. 

3.  The  closer  the  temperature  of  a  liquid  fuel  is  to  its  boiling  point, 
the  easier  and  faster  it  will  vaporize;  for  example,  gasoline  will  vaporize 
more  readily  in  summer  than  in  winter. 

The  Baume  Test. — Gasoline  is  usually  spoken  of  as  high  or  low  test. 
By  reference  to  the  principles  of  vaporization,  we  see  that  the  heavier 
a  liquid,  the  harder  it  is  to  evaporate.  This  principle  explains  the  reason 
for  the  use  of  the  Baume"  test.  A  hydrometer,  such  as  shown  in  Fig. 
95  is  graduated  in  degrees,  the  numbers  reading  from  the  bottom  up. 
These  degrees  have  nothing  to  do  with  thermometer  degrees,  but  are 
named  after  Baume,  who  originated  the  idea.  When  the  hydrometer  is 
placed  in  a  quantity  of  gasoline,  it  will  sink  to  a  depth  corresponding  to 
the  density  of  the  liquid.  It  will  sink  deeper  in  a  light  gasoline  than  in  a 
heavier  one.  The  deeper  the  hydrometer  sinks,  the  higher  the  scale  read- 
ing will  be.  This  scale,  reading  from  45  to  95°  Baume",  indicates  in  an 
indirect  way  the  ease  and  rapidity  with  which  the  gasoline  will  evapo- 
rate. It  is  not  a  direct  and  absolute  test  unless  the  nature  and  the 
boiling  points  of  the  crude  oil  from  which  the  gasoline  has  been  distilled 
are  known.  For  most  purposes,  however,  it  merely  serves  as  a  guide  as  to 
the  way  the  gasoline  will  act  in  service. 

Gasoline. — The  commercial  gasoline  of  today  has  a  Baume"  test  of 
from  50  to  65°,  the  better  or  high  test  being  in  the  neighborhood  of  65° 
and  the  poorer,  or  low  test,  in  the  neighborhood  of  50°.  For  summer 


78 


THE  GASOLINE  AUTOMOBILE 


use,  the  low  test  or  heavier  gasoline  can  be  used  very  .well  because  it 
will  evaporate  with  comparative  ease  at  the  usual  summer  temperatures, 
but  in  the  winter  the  high  test  or  light  gasoline  is  to  be  preferred  because 
it  will  evaporate  more  easily  at  the  low  temperatures.  More  work  can 
be  obtained  from  a  gallon  of  the  heavier  or  low  test  gasoline,  providing  it  is 
completely  vaporized,  but  it  is  very  difficult  to  vaporize  at  low  tempera- 
tures and  consequently  makes  starting  very  hard  in  cold  weather. 


Kerosene  Gasoline 

FIG.  95. — Baum6  hydrometer  in  kerosene  and  gasoline. 

Occasionally,  a  low  grade,  impure  gasoline  is  sold  which  lacks  sufficient 
refinement  and  purification,  the  sulphur  and  other  impurities  not  having 
been  eliminated.  The  use  of  this  may  result  in  carbon  deposits  in  the 
cylinders.  A  gasoline  that  readily  carbonizes  should  be  avoided  and  a 
higher  grade  used. 

Kerosene  and  Alcohol. — To  use  either  of  these  fuels  requires  the  heating 
of  the  fuel  or  the  air,  or  both,  in  order  to  secure  vaporization.  At  pres- 
ent, the  price  of  alcohol  is  too  high  to  warrant  giving  any  serious  con- 
sideration to  its  use.  Several  more  or  less  successful  devices  have  been 
tried  for  using  kerosene,  but  the  varying  speeds  and  loads  of  the  auto- 


FUELS  AND  CARBURETTING  SYSTEMS  79 

mobile  engine  make  the  problem  of  controlling  the  heat  very  difficult. 
The  reductions  in  the  price  of  gasoline  in  the  past  2  or  3  years  and  the 
very  promising  prospects  for  a  greater  increase  in  the  supply  and  corre- 
sponding reduction  in  the  price,  make  it  unlikely  that  any  great  develop- 
ment in  the  use  of  kerosene  will  take  place.  Consequently,  the  discussion 
to  follow  will  deal  only  with  gasoline  and  its  vaporization. 

53.  Heating  Value  of  Fuels. — The  heating  value,  or  the  amount  of 
heat  energy  contained  in  a  liquid  fuel,  is  given  in  British  thermal  units 
per  pound;  a  British  thermal  unit,  or  a  B.t.u.,  being  the  quantity  of 
heat  energy  required  to  raise  the  temperature  of  1  Ib.  of  water  1°  on  the 
Fahrenheit  scale.  The  following  table  gives  the  heating  values  of  the 
common  fuels: 

Gasoline  18,000  to  19,500  B.t.u.  per  pound. 
Kerosene  about  20,000  B.t.u.  per  pound, 
grain  about  10,000  B.t.u.  per  pound. 


Alcohol  ^  wQod  about    7)5(X)  B  t  u  per  pound 

Inasmuch  as  the  heavier  fuel  contains  more  pounds  per  gallon,  and  as 
gasoline  and  kerosene  are  sold  by  the  gallon,  a  gallon  of  heavy  or  low  test 
gasoline  or  of  kerosene  contains  more  energy  and  gives  more  power  than  a 
gallon  of  light,  or  high  test  gasoline. 

54.  Gasoline  Gas  and  Air  Mixtures. — It  is  necessary  when  the  gaso- 
line is  vaporized  that  it  be  mixed  with  the  proper  amount  of  air  to  form 
an  explosive  mixture.     If  too  little  air  is  furnished,  there  will  not  be  enough 
oxygen  to  burn  the  carbon  and  hydrogen  in  the  fuel  and  the  fuel  will  be 
wasted,  as  will  be  indicated  by  black  smoke  coming  from  the  exhaust. 
If  too  much  air  is  furnished,  the  mixture  is  weak  in  fuel,  giving  a  very  slow 
combustion.     This  results  in  lost  power.     A  weak  mixture,  or  an  excess  of 
air,  is  indicated  by  back-firing  through  the  carburetor. 

A  definite  mixture  of  gasoline  gas  and  air  is  necessary  for  the  efficient 
operation  of  a  gasoline  engine.  The  function  of  the  carburetor  is  to  take 
the  gasoline,  vaporize  it,  and  furnish  the  proper  mixture  of  gas  and  air  to 
the  cylinders  under  all  conditions  of  temperature,  speed,  load,  power  and 
varying  atmospheric  conditions. 

55.  Principles  of  Carburetor  Construction. — Most   of  the   modern 
types  of  carburetors  are  of  the  spray  or  nozzle  type,  in  which  a  jet  of  gaso- 
line is  sprayed  into  a  current  of  air  to  form  an  explosive  mixture.     Figure 
96  illustrates  an  elementary  spray  carburetor.     The  gasoline  supply  tank 
is  placed  below  the  carburetor  and  the  gasoline  is  pumped  up  through  the 
supply  pipe.      The  overflow  pipe  maintains  the  level  of  the  liquid  at  a 
constant  height.     The  standpipe  T  is  connected  with  the  supply  chamber 
C  by  means  of  the  connection  N  and  the  flow  is  regulated  by  the  needle 
valve  S.     The  gasoline  level  in  the  standpipe  T  is  always  the  same. 
The  flange  B  is  fastened  onto  the  intake  passage  of  the  engine.     The  sue- 


80 


THE  GASOLINE  AUTOMOBILE 


tion  of  the  piston  draws  air  through  the  opening  A  upward  past  the  stand- 
pipe,  and  at  the  same  time  draws  a  spray  of  gasoline  from  T.  The  but- 
terfly valve  D  is  for  the  purpose  of  regulating  the  suction  upon  the  stand- 
pipe  T  when  starting  the  engine;  when  running,  the  valve  D  should  be 
wide  open.  The  mixture  is  changed  by  regulating  the  needle  valve  8. 
This  type  of  carburetor  can  be  used  only  on  constant  speed  engines,  the 
reason  for  which  we  will  see  later.  Figure  97  shows  another  elementary 
type  of  carburetor  which  illustrates  the  application  of  two  modern  ideas. 
In  this  case,  the  gasoline  supply  is  maintained  at  a  constant  level  by 
means  of  a  hollow  metal  or  a  cork  float  operating  a  ball  valve.  The 


Fro.  96. 


FIG.  97. 


arrangement  requires  the  gasoline  supply  tank  to  be  placed  above  the 
carburetor  or  that  some  other  means  be  provided  for  supplying  gasoline 
under  pressure.  It  will  also  be  noticed  that  the  passage  surrounding  the 
standpipe  or  spray  nozzle  is  contracted,  giving  the  inside  surface  a  convex 
shape.  This  is  the  application  of  the  well  known  Venturi  tube  principle. 
By  contracting  the  section  near  the  opening  of  the  nozzle  the  velocity  of 
the  incoming  air  and  consequently  the  suction  at  that  point  are  increased, 
making  it  much  easier  for  the  gasoline  to  be  taken  up  and  greatly  facili- 
tating the  starting  of  an  engine  when  the  suction  is  low. 

This  type  of  carburetor  could  be  used  on  constant  speed  engines  only. 
If  a  carburetor  such  as  shown  in  Figs.  96  or  97  was  put  on  a  variable  speed 
engine  and  the  proper  adjustment  made  by  means  of  the  needle  valve  so 
that  the  mixture  proportions  were  correct  at  low  speed,  and  the  engine 
should  then  be  speeded  up,  we  would  discover  black  smoke  coining  from 
the  exhaust,  indicating  an  excess  of  gasoline  over  the  air  supplied.  This  is 
due  to  the  fact  that  under  the  increased  suction  due  to  the  higher  speeds 
of  the  piston,  the  air  drawn  in  past  the  standpipe  expands  and  increases 
in  volume  and  velocity  faster  than  it  increases  in  weight;  while  the  gasoline 
drawn  from  the  nozzle,  being  a  liquid,  increases  in  weight  just  as  its 
velocity  and  volume  are  increased.  This  means  that  under  an  increased 
suction  too  much  gasoline  is  supplied  for  the  amount  of  air  drawn  in. 


FUELS  AND  CARBURETTING  SYSTEMS  81 

In  order  to  keep  the  mixture  of  the  proper  proportions  at  all  speeds  of  the 
engine,  it  is  necessary  to  have  an  auxiliary  air  entrance,  such  as  indicated 
at  X  in  Fig.  98,  to  admit  an  additional  amount  of  air  at  the  higher  engine 
speeds.  This  entrance  is  usually  in  the  form  of  a  valve  controlled  by  a 
spring,  the  tension  on  which  can  be  changed  to  control  the  air  admission. 
For  low  speed  adjustments  the  gasoline  needle  valve  is  to  be  used,  and  for 
high  speed  adjustments  the  auxiliary  air  valve  is  to  be  adjusted.  That  is, 
when  the  engine  is  running  comparatively  slowly,  the  air  is  taken  in 
through  the  ordinary  air  opening  A  shown  below  the  valve  in  Fig.  98. 


FIG.  98.  FIG.  99. 

FIGS.  98  AND  99. — Sections  of  typical  variable  speed  carburetors. 

The  mixture  is  then  proportioned  by  means  of  the  needle  valve  NV. 
When  the  engine  speeds  up,  and  the  suction  is  increased,  the  auxiliary  air 
valve  S  in  Fig.  98  comes  into  action  and  opens.  If  it  is  found  that  the 
mixture  at  high  speeds  is  too  rich,  that  is  if  there  is  too  much  fuel  for  the 
air  furnished,  it  indicates  that  the  tension  on  the  valve  spring  is  too  great, 
which  prevents  sufficient  air  from  entering.  By  reducing  the  tension,  the 
valve  opens  wider,  letting  in  sufficient  air  to  keep  the  mixture  uniform. 
If  the  mixture  is  too  weak  at  high  speeds,  the  spring  tension  is  too  weak. 
It  should  be  tightened  so  as  to  permit  less  air  to  enter  and  to  increase  the 
suction  on  the  gasoline. 

The  following  general  description  applies  to  Fig.  98. 

G  =  gasoline  feed  from  tank. 
FV  =  float  valve  controlling  flow  of  gasoline  to  carburetor. 

F  =  float,  the  height  of  which  is  regulated  by  the  level  of  gasoline  in  the  float 

chamber.     The  float  controls  the  float  valve  FV. 

NV  =  gasoline  needle  valve  for  regulating  the  amount  of  gasoline  furnished  to  the 
air  in  the  mixing  chamber. 

N  =  gasoline  nozzle. 

X  =  auxiliary  air  valve,  to  admit  additional  air  at  the  high  speeds. 

S  =  spring  for  X. 

A  =  primary  air  opening,  which  supplies  all  air  at  low  speeds. 

T  =  throttle  valve  for  regulating  supply  of  mixture  from  carburetor  to  cylinder. 

P  =  primer  for  depressing  float  and  flooding  carburetor  to  insure  rich  mixture 
when  starting. 


82 


THE  GASOLINE  AUTOMOBILE 


Figure  99  shows  another  carburetor,  in  which  the  auxiliary  air  is  ad- 
mitted through  ports  X  controlled  by  steel  balls  B. 

Some  of  the  modern  types  of  carburetors  are  water-jacketed,  taking 
the  hot  water  from  the  cooling  system,  in  order  to  heat  the  carburetor 
and  assist  the  vaporization.  Another  method  of  assisting  the  vapori- 
zation, and  one  almost  necessary  when  the  low  grade  gasoline  of  today 
is  considered,  is  that  of  heating  the  air  which  goes  into  the  carburetor. 
This  is  usually  done  by  taking  it  through  a  jacket  surrounding  the  ex- 
haust pipe.  Figure  100  shows  such  a  device. 


FIG.  100. — Hot-air  connection  used  with  Master  carburetor. 

Another  scheme  used  in  several  of  the  carburetors  built  for  high 
powered,  high  speed  machines  is  the  double-jet,  which  makes  it  easier 
for  the  engine  to  draw  the  desired  amounts  of  gasoline  and  air  when  it 
becomes  necessary  for  the  engine  to  carry  heavy  loads  at  high  speed. 
Several  of  these  are  illustrated  in  the  following  articles,  which  describe 
some  of  the  leading  carburetors  now  in  use. 


FIG.  101.— Schebler  Model  L  carburetor. 

56.  Schebler  Model  L  Carburetor.— The  Model  L  carburetor,  Figs. 
101  and  102,  is  of  the  lift-needle  type  and  is  so  designed  that  the  amount 
of  fuel  entering  the  motor  is  controlled  by  means  of  a  raised  needle  work- 
ing automatically  with  the  throttle.  The  flow  of  gasoline  can  be  adjusted 


FUELS  AND  CARBURETTING  SYSTEMS 


83 


for  closed,  intermediate,  or  open  throttle  positions,  each  adjustment  being 
independent  and  not  affecting  either  of  the  others.  This  carburetor 
has  an  automatic  air  valve,  shown  at  the  left  in  Fig.  102.  At  high  speeds 
or  heavy  loads,  the  suction  raises  this  valve  and  admits  an  extra  supply  of 
air.  The  opening  of  the  throttle  for  high  speed  or  a  heavy  pull  raises 
the  needle  and  increases  the  supply  of  gasoline  to  correspond  with  the 
increased  air  supply. 

The  Model  L  can  be  furnished  with  a  bend  for  connecting  or  taking 
warm  air  from  around  the  exhaust  manifold  into  the  initial  air  opening  at 
the  base  of  the  carburetor,  by  means  of  a  hot  air  drum  and  tubing. 


FIG.  102. — Section  of  Shebler  Model  L  carburetor. 

This  carburetor  is  also  manufactured  with  a  dash-control  to  the  air 
valve  spring,  this  being  operated  by  a  lever  which  is  controlled  by  a 
switch  on  the  dashboard  or  steering  post  of  the  car.  This  control  is 
shown  on  Fig.  102. 

Rules  for  Adjusting  Schebler  Model  L. — The  carburetor  should  be 
connected  to  the  intake  manifold  so  that  it  is  located  below  the  bottom  of 
the  gasoline  tank  a  sufficient  distance  to  be  filled  by  gravity  under  all 
running  conditions.  Where  pressure  feed  is  used,  it  is  unnecessary  to 
locate  the  carburetor  below  the  gasoline  tank;  also,  when  pressure  is  used, 
it  is  never  advisable  to  carry  over  2  Ib. 

Before  adjusting  the  carburetor,  make  sure  that  the  ignition  is  prop- 
erly timed;  that  there  is  a  good  hot  spark  at  each  plug;  that  the  valves  are 
properly  timed  and  seated;  that  all  connections  between  the  intake  valves 
and  the  carburetor  are  tight;  and  that  there  are  no  air  leaks  of  any  kind 


84  THE  GASOLINE  AUTOMOBILE 

in  these  connections.  The  carburetor  should  be  adjusted  to  the  motor 
under  normal  running  temperature,  and  not  to  a  cold  motor. 

In  adjusting  the  carburetor,  first  make  the  adjustments  on  the  auxili- 
ary air  valve  so  that  the  air  valve  seats  lightly  but  firmly.  The  lever  on 
the  dash  control  should  be  set  in  the  center  of  the  dashboard  adjuster, 
and  with  this  setting  of  the  lever,  the  tension  on  the  air  valve  should  be 
light,  yet  firm.  Close  the  needle  valve  by  turning  the  adjustment  screw 
to  the  right. until  it  stops.  Do  not  use  any  pressure  on  this  adjustment 
screw  after  it  meets  with  resistance.  Then  turn  it  to  the  left  about  four 
or  five  turns  and  prime  or  flush  the  carburetor  by  pulling  up  the  priming 
lever  and  holding  it  up  for  about  5  seconds;  Next,  open  the  throttle 
about  one-third  and  start  the  motor;  then  close  the  throttle  slightly, 
retard  the  spark,  and  adjust  the  throttle  lever  screw  and  the  needle 
valve  adjusting  screw,  so  that  the  motor  runs  at  the  desired  speed  and 
hits  on  all  cylinders. 

After  getting  a  good  adjustment  with  the  motor  running  idle  do  not 
touch  the  needle  valve  adjustment  again,  but  make  your  intermediate 
and  high  speed  adjustments  on  the  dials.  Adjust  the  pointer  on  the  first 
dial  about  half  way  between  figure  1  and  figure  3.  Advance  the  spark 
and  open  the  throttle  so  that  the  roller  on  the  track  running  below  the 
dials  is  in  line  with  the  first  dial.  If  the  motor  back-fires  with  the  throttle 
in  this  position  and  the  spark  advanced,  turn  the  indicator  a  little  more 
toward  figure  3;  if  the  mixture  is  too  rich,  turn  the  indicator  back,  or 
toward  figure  1,  until  you  are  satisfied  that  the  motor  is  running  properly 
with  the  throttle  in  this  position,  or  at  intermediate  speed.  Now  open  the 
throttle  wide  and  make  the  adjustment  on  the  second  dial  for  high  speed 
in  the  same  manner  as  you  have  made  the  adjustments  for  intermediate 
speed  on  the  first  dial. 

67.  Schebler  Model  R.— The  Model  R  Schebler  carburetor,  Fig.  103, 
is  designed  for  use  on  both  four-  and  six-cylinder  motors.  It  is  a  single-jet 
raised-needle  type  of  carburetor,  automatic  in  action.  The  air  valve 
controls  the  lift  of  the  needle  so  as  to  automatically  proportion  the  amount 
of  gasoline  and  air  at  all  speeds. 

The  Model  R  carburetor  is  designed  with  an  adjustment  for  low  speed. 
As  the  speed  of  the  motor  increases,  the  air  valve  opens,  raising  the  gaso- 
line needle  and  thus  automatically  increasing  the  amount  of  fuel.  This 
carburetor  has  but  two  adjustments,  the  low  speed  needle  adjustment, 
which  is  made  by  turning  the  air  valve  cap,  and  an  adjustment  on  the  air 
valve  spring  for  changing  its  tension. 

The  Model  R  carburetor  has  an  eccentric  which  acts  on  the  needle 
valve,  intended  to  be. operated  either  from  the  steering  column  or  from  the 
dash,  and  insures  easy  starting,  as,  by  raising  the  needle  from  the  seat, 
an  extremely  rich  mixture  is  furnished  for  starting  and  for  heating  up  the 


FUELS  AND  CARBURETTING  SYSTEMS 


85 


motor  in  cold  weather.  A  choke  valve  in  the  air  bend  is  also  furnished. 
The  dashboard  control  or  steering  column  control  must  be  used  with  this 
carburetor;  it  cannot  be  operated  satisfactorily  without  them. 

Rules  for  Adjusting  Model  R  Carburetor. — When  the  carburetor  is 
installed,  see  that  lever  B  is  attached  to  the  steering  column  control  or 
dash  control  so  that  when  boss  D  of  lever  B  is  against  stop  C  the  lever  on 
the  steering  column  control  or  dash  control  will  register  "Lean"  or  "Air." 
This  is  the  proper  running  position  for  lever  B. 


FIG.  103.— Schebler  Model  R  carburetor. 

To  adjust  the  carburetor  turn  the  air  valve  cap  A  clockwise  or  to  the 
right  until  it  stops,  then  turn  it  to  the  left  or  anti-clockwise  one  complete 
turn. 

To  start  the  engine,  open  the  throttle  about  one-eighth  or  one-quarter 
way.  When  the  engine  is  started,  let  it  run  till  it  is  warmed,  then  turn  the 
air  valve  cap  A  to  the  left  or  anti-clockwise  until  the  engine  hits  perfectly. 
Advance  the  spark  three-quarters  of  the  way  on  the  quadrant;  then  if  the 
engine  back-fires  on  quick  acceleration,  turn  the  adjusting  screw  F  up 
(which  increases  the  tension  on  the  air  valve  spring)  until  acceleration  is 
satisfactory. 

Turning  the  air  valve  cap  A  to  the  right  or  clockwise  lifts  the  needle  E 
out  of  the  nozzle  and  enriches  the  mixture;  turning  to  the  left  or  anti- 
clockwise lowers  the  needle  into  the  nozzle  and  makes  the  mixture  lean. 


86  THE  GASOLINE  AUTOMOBILE 

When  the  motor  is  cold  or  the  car  has  been  standing,  move  the  steer- 
ing column  or  dash  control  lever  toward  "Gas"  or  "Rich."  This  oper- 
ates the  lever  B  and  lifts  the  needle  E  out  of  the  gasoline  nozzle  and  makes 
a  rich  mixture  for  starting.  As  the  motor  warms  up,  move  the  control 
lever  gradually  back  toward  "Air"  or  "Lean"  to  obtain  best  running 
conditions,  until  the  motor  has  reached  normal  temperature.  When 
this  temperature  is  reached,  the  control  lever  should  be  at "  Air  "  or  "Lean." 
For  best  economy,  the  slow  speed  adjustment  should  be  made  as  lean  as 
possible. 

68.  The  Holley  Model  H  Carburetor. — This  carburetor  is  shown 
in  Fig.  104.  Before  the  fuel  enters  the  float  chamber,  it  passes  a  strainer 


FIG.  104.— Holley  Model  H  carburetor. 


disc  A  which  removes  all  foreign  matter  that  might  interfere  with  the 
seating  of  the  float  valve  B  under  the  action  of  the  cork  float,  and  its 
lever  C. 

Fuel  passes  from  the  float  chamber  D  into  the  nozzle  well  E  through  a 
passage  F  drilled  through  the  wall  separating  them.  From  the  nozzle 
well,  the  fuel  enters  the  cup  G  through  the  hole  H,  and  rises  past  the  needle 
valve,  /,  to  a  level  which  partially  submerges  the  lower  end  of  a  small 
tube,  J,  having  its  outlet  K  at  the  edge  of  the  throttle  disc. 


FUELS  AND  CARBURETTING  SYSTEMS  87 

Cranking  the  engine,  with  the  throttle  kept  nearly  closed,  causes  a 
very  energetic  flow  of  air  through  the  tube  J  and  its  calibrated  throttling 
plug  K.  But  with  the  engine  at  rest  the  lower  end  of  this  tube  is  partially 
submerged  in  fuel.  Therefore,  the  act  of  cranking  automatically  primes 
the  motor.  With  the  motor  turning  over  under  its  own  power,  flow 
through  the  tube  J  takes  place  at  very  high  velocity,  thus  causing  the  fuel 
entering  the  tube  with  the  air  to  be  thoroughly  atomized  upon  its  exit 
from  the  small  opening  at  the  throttle  edge.  This  tube  is  called  the 
"low  speed  tube"  because,  for  starting  and  idle  running,  all  of  the  fuel 
and  most  of  the  air  in  the  working  mixture  are  taken  through  it. 

As  the  throttle  opening  is  increased  beyond  that  needed  for  idling  of 
the  motor,  a  considerable  volume  of  air  is  drawn  down  around  the  outside 
of  the  strangling  tube  L  and  then  upward  through  this  tube.  In  its  pas- 
sage into  the  strangling  tube,  the  air  is  made  to  assume  an  annular,  con- 
verging stream  form,  so  that  the  point  in  its  flow  at  which  it  attains  its 
highest  velocity  is  in  the  immediate  neighborhood  of  the  upper  end  of 
the ' '  standpipe  "  M .  The  velocity  of  air  flow  being  highest  at  the  upper  or 
outlet  end  of  the  standpipe,  the  pressure  in  the  air  stream  is  lowest  at  the 
same  point.  For  this  reason,  there  is  a  pressure  difference  between  the 
top  and  bottom  openings  of  the  pipe  M ,  thus  causing  air  to  flow  through 
it  from  bottom  to  top,  the  air  passing  downward  through  the  openings 
N  in  the  bridge  supporting  the  standpipe  and  then  up  through  the 
standpipe. 

With  a  very  small  throttle  opening,  the  action  through  the  standpipe 
keeps  the  nozzle  cup  thoroughly  cleaned  out,  the  fuel  being  carried  directly 
from  the  needle  opening  into  the  entrance  of  the  standpipe. .  To  secure 
the  best  vaporization  of  the  fuel,  the  passage  through  the  standpipe  is 
given  an  aspirator  form,  which  further  increases  the  velocity  of  flow 
through  it,  and  insures  the  greatest  possible  mixing  of  the  fuel  with  the 
air.  A  further  point  is  that  the  vaporized  discharge  of  the  standpipe 
enters  the  main  air  stream  at  the  point  at  which  the  latter  attains  its 
highest  velocity  and  lowest  pressure. 

There  is  but  one  adjustment,  that  of  the  needle  valve  /.  The  effect 
of  a  change  in  its  setting  is  manifest  over  the  whole  range  of  the  motor. 

59.  Holley  Model  G. — This  carburetor,  Fig.  105,  is  a  special  design 
for  Ford  cars. 

The  operation  of  this  carburetor  is  the  same  as  the  regular  Model  H 
already  illustrated  and  described.  The  chief  differences  are  the  structural 
ones  giving  a  horizontal  instead  of  a  vertical  outlet,  a  needle  valve  con- 
trolled from  above  instead  of  from  below,  and  a  simplification  of  design  to 
secure  compactness. 

Fuet  enters  the  carburetor  by  way  of  a  float  mechanism  in  which  a 
hinged  ring  float,  in  rising  with  the  fuel,  raises  the  float  valve  into  contact 


88  THE  GASOLINE  AUTOMOBILE 

with  its  seat.     This  seat  is  removable  and  the  float  valve  is  provided  with 
a  tip  of  hard  material. 

From  the  float  chamber  the  gasoline  passes  through  the  ports  E  to 
the  nozzle  orifice,  in  which  is  located  the  pointed  end  of  the  needle  F. 
The  ports  E  are  well  above  the  bottom  of  the  float  chamber,  so  that,  even 
should  water  or  other  foreign  matter  enter  the  float  chamber,  it  would 
have  to  be  present  in  very  considerable  quantity  before  it  could  interfere 
with  the  operation  of  the  carburetor.  A  drain  valve  D  is  provided  for 
the  purpose  of  drawing  off  whatever  sediment  or  water  may  accumulate 
in  the  float  chamber. 


FIG.  105.— Holley  Model  G  carburetor. 

The  float  level  is  so  set  that  the  gasoline  rises  past  the  needle  valve  F 
and  sufficiently  fills  the  cup  G  to  submerge  the  lower  end  of  the  small  tube 
H.  Drilled  passages  in  the  casting  communicate  the  upper  end  of  this 
tube  with  an  outlet  at  the  edge  of  the  throttle  disc.  The  tube  and  passage 
give  the  starting  and  idling  actions,  as  described  in  connection  with  the 
Holley  Model  H. 

The  strangling  tube  /  gives  the  entering  air  stream  an  annular  con- 
verging form,  in  which  the  lowest  pressure  and  highest  velocity  occur 
immediately  above  the  cup  G;  thus  it  is  seen  that  the  fuel  issuing  past  the 
needle  valve  F  is  immediately  picked  up  by  the  main  air  stream,  at  the 
point  of  the  latter's  highest  velocity. 

The  lever  L  operates  the  throttle  in  the  mixture  outlet.  A  larger  disc 
with  its  lever  S  forms  a  spring-returned  choke  valve  in  the  air  intake,  for 
starting  in  extremely  cold  weather. 


FUELS  AND  CARBU RETTING  SYSTEMS 


89 


60.  Stewart  Model  25. — This  carburetor,  which  is  manufactured  by 
the  Detroit  Lubricator  Company,  involves  an  interesting  principle  of 
operation. 

Figure  106  gives  a  cross  section  of  this  carburetor  and  shows  the  posi- 
tion of  the  air  valve  with  engine  running  and  air  and  gasoline  being 
admitted. 

With  the  engine  at  rest  and  no  air  passing  through  the  carburetor,  the 
air  valve  A  rests  on  the  seat  B,  closing  the  main  air  passage.  The  gasoline 
rises  to  a  height  of  about  1^  in.  below  the  top  of  the  central  aspirating 


FIG.  106. — Stewart  Model  25  carburetor. 

tube  L.  As  soon  as  the  engine  starts  to  rotate,  a  partial  vacuum  is  formed 
above  the  air  valve,  causing  it  to  lift  from  its  seat  and  admit  air,  at  the 
same  time  gasoline  being  drawn  up  through  the  aspirating  tube  L.  The 
lower  end  of  the  air  valve  extends  down  into  the  gasoline  and  around  the 
metering  pin  P.  Due  to  the  decreasing  diameter  of  this  pin,  the  higher 
the  air  valve  is  lifted  the  larger  will  be  the  opening  into  the  tube  L,  and 
the  more  gasoline  will  be  drawn  up.  The  upper  end  of  the  air  valve  meas- 
ures the  air,  the  lower  end  measures  the  gasoline;  therefore,  as  the  suction 
varies,  the  air  valve  moves  up  or  down  and  the  volume  of  air  and  the 
amount  of  gasoline  admitted  to  the  mixing  chamber  increase  or  decrease 
in  the  same  ratio.  Most  of  the  air  passing  through  the  carburetor  goes 
through  the  air  passages  as  indicated  by  the  black  arrows.  A -small 
amount  is  drawn  through  the  drilled  holes  HH  and  past  the  end  of  the 


90 


THE  GASOLINE  AUTOMOBILE 


tube  L.  The  flared  end  of  this  tube  deflects  the  air  through  a  small  an- 
nulus,  thereby  increasing  the  velocity  of  air  at  this  point  so  as  to  aid  in 
atomizing  the  fuel. 

The  air  valve  is  restrained  from  any  tendency  to  flutter,  caused  by  the 
intermittent  suction  of  the  cylinders,  by  the  dash  pot  D.  Due  to  the 
greater  inertia  of  the  gasoline  and  because  it  flows  comparatively  slowly 
through  the  small  opening  and  into  the  dash  pot,  the  air  valve  can  rise  or 
fall  only  as  liquid  is  expelled  or  admitted  and  thus  the  air  valve  is  held 
steady.  The  Stewart  carburetors  have  but  one  adjustment,  which  raises 
or  lowers  the  metering  pin,  thereby  decreasing  or  increasing  the  amount  of 
gasoline  admitted  to  the  mixing  chamber.  The  correct  position  of  the 
metering  pin  is  determined  with  the  motor  running  at  idling  speed.  This 
adjustment  may  be  manipulated  at  the  dash  to  compensate  for  extreme 
changes  in  atmospheric  temperatures  and  for  use  in  starting  in  cold 
weather. 

61.  Kingston  Model  L. — Figure  107  shows  the  construction  of  this  car- 
buretor. Gasoline  enters  the  carburetor  from  the  tank  at  the  connection 
A  and  is  maintained  at  a  constant  level,  through  the  agency  of  the  float. 

A  pool  of  gasoline  forms  in  the  base  of 
the  U-shaped  mixing  tube  and  will  always 
be  present  when  the  motor  is  not  run- 
ning. This  aids  in  positive  starting. 
When  the  motor  starts,  this  pool  is 
quickly  lowered  to  the  point  of  adjust- 
ment of  the  needle  valve  and  continues 
to  feed  from  this  point  till  the  motor  is 
stopped. 

When  the  motor  is  running  slowly, 
the  air  valve  B  rests  lightly  on  its  seat, 
allowing  no  air  to  pass  through;  con- 
sequently all  air  must  pass  through  the 
low  speed  mixing  tube  C.  Due  to  the  lower  end  of  this  tube  being  close 
to  the  spray  nozzle  and  all  the  low  speed  air  having  to  pass  this  point, 
the  atomized  gasoline  drawn  from  nozzle  D  becomes  thoroughly  mixed 
with  air  in  its  upward  course  and  is  carried  in  this  state  to  the  motor. 
When  the  throttle  is  opened  slowly,  the  following  action  takes  place. 
The  motor  now  requires  a  greater  volume  of  mixture.  The  air  valve  B 
slowly  leaves  its  seat,  permitting  an  extra  air  supply  to  enter  and  compen- 
sate for  the  increased  flow  of  gasoline  produced  by  the  greater  suction  of 
the  motor.  In  this  carburetor  the  extra  amount  of  gasoline  for  the 
starting  and  warming  up  period  can  be  obtained  by  opening  the  needle 
valve  .adjustment  at  the  dash  or  by  the  use  of  the  choke  throttle  E  placed 
in  the  air  passage, 


FIG.  107.— Kingston  Model  L 
carburetor. 


FUELS  AND  CARBURETTING  SYSTEMS  91 

When  starting  with  a  cold  motor,  this  choke  throttle  can  be  closed  by 
pulling  the  wire  forward.  This  cuts  off  nearly  all  the  air  supply  and  pro- 
duces a  very  strong  suction  at  the  spray  nozzle,  which  causes  the  gasoline 
to  jet  up  and  be  carried  with  the  incoming  rush  of  air  to  the  cylinders. 

A  drain  cock  G  is  placed  at  the  lowest  point  in  the  bowl  and  should  be 
opened  from  time  to  time  to  free  the  bowl  of  all  water  and  foreign  matter. 

Rules  for  A  djusting  Kingston  Model  L. — Retard  the  spark  fully.  Open 
the  throttle  about  five  or  six  notches  of  the  quadrant  on  the  steering  post. 
Loosen  the  needle  valve  binder  nut  on  the  carburetor  until  the  needle  valve 
turns  easily..  Turn  the  needle  valve  (with  dash  adjustment)  until  it 
seats  lightly.  Do  not  force  it.  Adjust  it  away  from  its  seat  one  com- 
plete turn.  This  will  be  slightly  more  than  necessary  but  will  assist  in 
easy  starting. 

Start  the  motor  and  open  or  close  the  throttle  until  the  motor  runs  at 
fair  speed,  not  too  fast,  and  allow  it  to  run  long  enough  to  warm  up  to 
service  conditions.  Now  make  the  final  adjustment.  This  carburetor 
has  but  one  adjustment — the  needle  valve.  Close  the  throttle  until  the 
motor  runs  at  the  desired  idling  speed.  This  can  be  controlled  by  ad- 
justing the  stop  screw  in  the  throttle  lever. 

Adjust  the  needle  valve  toward  its  seat  slowly  until  the  motor  begins 
to  lose  speed,  thus  indicating  a  weak  or  lean  mixture.  Now  adjust  the 
needle  valve  away  from  its  seat  very  slowly  until  the  motor  attains  its 
best  and  most  positive  speed.  This  should  complete  the  adjustment. 
Close  the  throttle  until  the  motor  runs  slowly,  then  open  it  rapidly.  The 
motor  should  respond  strongly.  Should  the  acceleration  seem  slightly 
weak  or  sluggish,  a  slight  adjustment  of  the  needle  valve  may  be  advisable 
to  correct  this  condition.  With  the  adjustment  completed,  tighten  the 
binder  nut  until  the  needle  valve  turns  hard. 

62.  Marvel  Carburetor. — The  Marvel,  shown  in  Fig.  108,  is  of  the 
double  nozzle  type,  the  second  nozzle  coming  into  action  at  high  speeds. 
At  low  speeds  all  the  air  is  drawn  through  the  venturi  tube,  where  it  takes 
up  gasoline  from  the  primary  nozzle.  At  high  speeds  after  the  air  has 
passed  the  choke  damper,  it  divides,  part  of  it  going  through  the  venturi 
tube  around  the  low  speed  spray  nozzle,  and  the  remainder  passing  to  one 
side  and  opening  the  auxiliary  valve  against  the  pressure  of  its  spring. 
Near  the  top  of  the  auxiliary  air  valve  is  the  secondary  or  high  speed 
spray  nozzle. 

The  rush  of  air  through  the  venturi  tube  picks  up  and  vaporizes  the 
gasoline  from  the  low  speed  nozzle  and  carries  it  in  suspension  past  the 
throttle  and  to  the  cylinders.  When  the  suction  at  the  auxiliary  air  valve 
has  increased  sufficiently  to  open  this  valve  and  create  a  high  velocity  at 
this  point,  gasoline  is  also  picked  up  from  the  high  speed  nozzle  and  car- 
ried to  the  cylinders  in  like  manner, 
10 


92 


THE  GASOLINE  AUTOMOBILE 


The  choke  damper  in  the  air  inlet  is  used  only  for  starting  the  motor, 
by  partially  shutting  off  the  air  supply  and  forcing  the  motor  to  suck  in  a 
rich  mixture. 

To  the  throttle  is  connected  a  hot  air  damper,  which  when  open  al- 
lows the  exhaust  gas  from  the  motor  to  flow  through  a  cored  passage 
around  the  throttle,  where  it  heats  the  mixture  of  gasoline  and  air.  A 
tube  connects  this  passage  with  another  which  surrounds  the  venturi  tube 
and  spray  nozzle,  and  provides  heat  for  the  incoming  fuel  and  air. 


Hot  air  jacket 

xing  chamber      ^ 


,7~hr 


ottle 


throttle 
/  .   Hot  air  damper 


Auxiliary  air  valve 
Auxiliary  spray  nozzle 


~Neea'/e  valve 
"A" 


FIG.  108. — The  Marvel  carburetor. 


Rules  for  Adjusting  the  Marvel  Carburetor. — The  following  rules  for 
adjustment  are  given  by  the  manufacturers: 

Start  by  turning  the  needle  valve  A  to  the  right  until  it  is  completely 
closed,  and  the  air  adjustment  B  to  the  left  until  it  stops.  Now  give  the 
air  adjusting  screw  B  three  complete  turns  to  the  right,  and  open  the 
needle  valve  A  two  complete  turns  to  the  left.  Start  the  motor  as  usual, 
using  the  strangler  button  to  get  a  rich  mixture  at  first.  Close  the 
throttle  until  the  motor  runs  slowly  and  verify  the  needle  valve  adjust- 
ment A  by  turning  it  to  the  right  a  little  at  a  time  (%  to  %  of  a  turn  should 
be  sufficient)  until  the  motor  runs  smoothly  and  evenly.  At  this  point  the 
motor  should  be  allowed  to  run  until  thoroughly  warmed  up. 

After  the  motor  has  warmed  up,  turn  the  air  valve  adjusting  screw  B 
to  the  left,  a  little  at  a  time,  until  the  motor  begins  to  slow  down.  This 
indicates  that  the  air  valve  spring  is  too  loose.  Turn  it  back  to  the  right 
just  enough  to  make  the  motor  run  well. 

To  test  the  adjustment,  advance  the  spark  and  open  the  throttle 
quickly.  The  motor  should  "take  hold"  instantly  and  speed  up  at  once. 


FUELS  AND  CARBURETTING  SYSTEMS 


93 


If  it  misses  or  pops  back  in  the  carburetor,  open  needle  valve  A  slightly  by 
turning  to  the  left.  Do  not  move  the  air  adjusting  screw  B  any  more  un- 
less it  appears  absolutely  necessary. 

The  best  possible  adjustment  has  been  secured  when  the  air  adjust- 
ment B  is  turned  as  far  as  possible  to  the  left  and  the  needle  valve  A  is 
turned  as  far  as  possible  to  the  right,  providing  the  motor  runs  smoothly 
and  picks  up  quickly  when  the  throttle  is  opened. 


Mixture  RCGULATOfl  TUBE  HCU»  t  SCREW 


•*  AUXILIARY  GASOUNE  WELL  f 

t  GASOUNC  WELL  PLUG  GASKET 
[PRMARV  NOZZLE  NEEDLE  VALVE  (COMPLETE) 


FIG.  109. — Stromberg  Model  H  carburetor. 

If  the  motor  runs  too  fast  with  throttle  closed,  turn  the  small  set  screw 
in  throttle  stop  to  the  left.  If  the  motor  stops  when  the  throttle  is  fully 
closed,  turn  the  set  screw  to  the  right. 

As  the  throttle  opens,  the  hot  air  damper,  which  is  connected  to  it  by  a 
link,  gradually  closes,  the  greatest  amount  of  hot  air  passing  through  the 
jackets  when  the  throttle  is  nearly  closed.  The  position  of  the  hot  air 
damper  at  any  time  is  indicated  by  the  slot  at  the  end  of  the  damper 
shaft.  By  loosening  the  set  screw  in  the  damper  lever,  this  can  be  set 


94  THE  GASOLINE  AUTOMOBILE 

for  any  desired  relation  between  the  damper  and  the  throttle.     Ordinarily 
the  hot  air  damper  should  be  nearly  horizontal  when  the  throttle  is  closed. 

63.  Stromberg    Model  H. — The  Stromberg  Model   H   carburetor, 
shown  in  Fig.  109,  is  of  the  double-jet  type  with  two  adjustments,  for 
high  and  low  speed,  both  working  on  the  gasoline  supply. 

The  gasoline  in  the  glass  float  chamber  is  regulated  by  the  hollow  metal 
float.  The  fuel  for  low  speed  is  furnished  by  the  spray  nozzle  in  the  ven- 
turi  tube,  through  which  the  low  speed  air  passes.  The  adjustment  for 
this  nozzle  is  by  means  of  the  needle  valve,  as  shown. 

At  high  speed,  the  auxiliary  air  comes  through  the  auxiliary  air  valve, 
which  in  turn  automatically  regulates  the  gasoline  flow  from  the  auxiliary 
gasoline  valve.  This  supplies  the  extra  gasoline  for  high  speed  and  heavy 
duty  service. 

The  dash  pot  with  the  piston  riding  in  gasoline  prevents  all  fluttering 
of  the  air  valve  on  its  seat  when  opening  and  closing. 

This  type  of  carburetor  is  fitted  with  a  strangling  or  choke  valve  in 
the  primary  air  inlet,  for  starting  in  cold  weather.  This  assists  in  the 
vaporization  of  the  gasoline  by  increasing  the  suction  on  the  liquid. 

The  spring  tension  on  the  air  valve  and  auxiliary  needle  valve  is  con- 
trolled either  from  the  dash  or  from  the  steering  post,  depending  upon  the 
style  of  control  installed.  This  permits  adjustments  to  be  made  in  order 
to  compensate  for  varying  conditions  of  weather,  fuel,  and  operation. 

64.  Zenith  Model  L. — This  carburetor,  shown  in  Fig.  110,  differs  from 
most  conventional  types  in  the  absence  of  auxiliary  air  valves.     It  is  a 
"fixed"  adjustment  carburetor,   and  has  as  its  particular  feature  the 
"compound  nozzle."     The  compound  nozzle  consists  of  an  inner  nozzle, 
the  gasoline  for  which  is  furnished  direct  from  the  float  chamber.     The 
amount  of  gasoline  leaving  this  nozzle  varies  with  the  suction  and  conse- 
quently the  mixture  from  this  nozzle  would  be  too  rich  at  high  speeds. 
To  compensate  for  this  rich  mixture,  the  compensating  nozzle  surround- 
ing the  main  nozzle  furnishes  a  mixture  "too  weak "  at  high  speeds.     This 
is  because  the  gasoline  feed  to  this  jet  is  constructed  so  as  to  be  constant 
at  all  speeds.     When  the  engine  speeds  up,  the  amount  of  air  increases 
and  the  compensating  mixture  is  a  weak  one.     This  answers  the  purpose 
of  the  auxiliary  air  valve  on  other  types  of  carburetors  and  keeps  the 
mixture  of  constant  proportions.     By  a  proper  selection  of  the  two  nozzles 
a  well  balanced  mixture  can  be  secured  through  the  entire  range. 

In  addition  to  the  compound  nozzle,  the  Zenith  is  equipped  with  a 
starting  and  idling  well.  This  well  terminates  in  a  priming  hole  at  the 
edge  of  the  butterfly  valve,  where  the  suction  is  greatest  when  the  valve 
is  slightly  open.  The  gasoline  is  drawn  up  by  the  suction  at  the  priming 
hole  and,  mixed  with  the  air  rushing  by  the  butterfly,  gives  a  rich  slow 
speed  mixture.  The  slow  speed  mixture  is  regulated  by  the  regulating 


FUELS  AND  CARBURETTING  SYSTEMS 


95 


screw,  which  admits  air  to  the  priming  well.  At  higher  speeds  with  the 
butterfly  valve  opened,  the  priming  well  ceases  to  operate  and  the  com- 
pound nozzle  drains  the  well  and  compensates  for  any  engine  speed. 


Fia.  110.— Zenith  Model  L  carburetor. 

65.  Rayfield  Model  G. — This  carburetor  is  illustrated  in  Figs.  Ill  and 
112.  It  has  two  jets  and  the  gasoline  is  drawn  through  them  into 
the  mixing  chamber,  the  quantity  being  controlled  by  adjustments  on  the 
outside  of  the  carburetor.  As  will  be  noticed,  there  are  no  air  valve  ad- 
justments, but  two  gasoline  adjustments,  a  low  speed  adjustment  and  a 
high  speed  adjustment.  The  names  of  the  lettered  parts  on  Fig.  Ill  are 
as  follows: 


D  —Throttle  Arm. 
G  — Priming  Lever. 
H  —Gas  Arm. 


M  — Regulating  Cam. 
S  — Drain  Cock. 
U  — Needle  Valve  Arm. 
X  —Drain  Cocks. 


The  suction  created  by  the  downward  motion  of  the  motor  pistons 
draws  air  into  the  mixing  chamber  through  the  primary  and  auxiliary 
air  inlets.  This  air  rushes  through  the  mixing  chamber,  around  the  nozzle 


96 


THE  GASOLINE  AUTOMOBILE 


and  the  metering  pin,  and  picks  up  the  gasoline  which  leaves  the  nozzle 
and  jet  in  the  form  of  a  spray.  Thus  the  action  of  the  mixing  chamber  is 
not  unlike  that  of  an  ordinary  atomizer  in  which  the  air,  forced  from  the 
rubber  bulb,  picks  up  a  certain  amount  of  the  liquid  in  the  bottle  and 
sprays  it  out  in  the  form  of  a  fine  vapor. 

That  the  proportion  of  air  and  gasoline  in  the  mixture  may  be  correct 
for  all  motor  speeds,  one  fixed  air  inlet  and  two  variable  auxiliary  air 
inlets  are  provided.  The  lower  air  valve  opens  and  closes  with  the  main 
or  upper  automatic  air  valve,  giving  a  greater  volume  of  air  in  proportion 
to  the  greater  amount  of  gasoline  to  be  vaporized.  In  other  words,  at 
high  motor  speeds  or  when  the  throttle  is  fully  opened,  the  motor  requires 
more  gas  and  consequently  a  greater  volume  of  air  to  vaporize  the  gasoline 


HIGH    SPEED 
ADJUSTMENT 


FIG.  111.— Rayfield  Model  G  carburetor. 

which  comes  through  the  spray  nozzles;  at  low  mo  tor  speeds,  less  gas  is 
required  and  consequently  less  air  is  necessary  to  vaporize  the  gasoline. 

At  the  front  end  of  the  carburetor  is  the  main  auxiliary  air  valve. 
This  is  controlled  by  a  spring  and  dashpot.  At  low  speeds,  when  only  a 
small  amount  of  air  is  being  drawn  through  the  carburetor,  the  spring  and 
dashpot  hold  this  valve  almost  shut.  As  the  speed  increases  and  more 
air  is  needed,  the  suction  operating  against  the  tension  of  the  spring  draws 
the  valve  further  and  further  open,  thus  giving  an  increased  supply  of 
air  in  proportion  to  the  need  for  the  increased  speed.  The  motion  of  this 
valve  moves  the  metering  pin  and  admits  an  additional  supply  of  gasoline 
at  this  second  nozzle. 

Rules  for  Adjusting  Rayfield  Model  G.— With  throttle  closed,  and  dash 
control  down,  close  the  nozzle  needle  by  turning  the  low  speed  adjustment 


FUELS  AND  CARBURETTING  SYSTEMS 


97 


to  the  left  until  block  U  slightly  leaves  contact  with  the  cam  M .  Then 
turn  to  the  right  about  three  complete  turns.  Open  the  throttle  not  more 
than  one-quarter.  Prime  the  carburetor  by  pulling  steadily  a  few  seconds 
on  the  priming  lever  G.  Start  the  motor  and  allow  it  to  run  until  warmed 
up.  Then  with  retarded  spark,  close  the  throttle  until  the  motor  runs 
slowly  without  stopping.  Now,  with  the  motor  thoroughly  warm,  make 
the  final  low  speed  adjustment  by  turning  the  low  speed  screw  to  the  left 
until  the  motor  slows  down  and  then  turn  to  the  right  a  notch  at  a  time 
until  the  motor  idles  smoothly. 

To  make  the  high  speed  adjustment,  advance  the  spark  about  one- 
quarter.  Open  the  throttle  rather  quickly.  Should  the  motor  back-fire, 
it  indicates  a  lean  mixture.  Correct  this  by  turning  the  high  speed  ad- 
justing screw  to  the  right  about  one  notch  at  a  time,  until  the  throttle 
can  be  opened  quickly  without  back-firing. 


FIG.  112. — Section  of  Rayfield  Model  G  carburetor. 

If  "loading"  (choking)  is  experienced  when  running  under  heavy 
load  with  throttle  wide  open,  it  indicates  too  rich  a  mixture.  This  can  be 
overcome  by  turning  the  high  speed  adjustment  to  the  left. 

66.  Carter  Model  C. — The  Carter  carburetor,  shown  in  section  in 
Fig.  113,  is  of  unconventional  design  and  construction  in  many  ways. 
The  float  is  of  copper  and  is  spherical  in  shape.  The  float  valve  is  pro- 
vided with  a  shock  absorber  to  prevent  the  valve  from  pounding  on  its 
seat  when  the  car  is  being  driven  over  rough  roads. 

There  are  three  adjustments,  for  low,  intermediate,  and  high  speeds. 
The  adjustable  fuel  tube  gives  the  advantages  of  multiple  jets.  For  low 
speeds  the  air  taken  in  just  above  the  bottom  of  the  fuel  tube  takes 
gasoline  from  around  the  bottom  of  the  tube.  Under  increased  suction 
the  gasoline  is  sucked  higher  in  the  tube  and  is  sprayed  through  a  number 
of  openings  in  the  side  of  the  fuel  tube  into  the  air  coming  through  the 


98  THE  GASOLINE  AUTOMOBILE 

intermediate  air  valve.     The  high  speed  air  adjustment  is  made  from  a 
lever  connection  on  the  dash. 

67.  General  Rules  for  Carburetor  Adjustment.— Very  few  general 
rules  can  be  given  for  the  adjustment  of  a  carburetor.  It  is  usually  a 
very  wise  plan  to  let  well  enough  alone,  but  if  adjustments  are  necessary, 
it  is  very  essential  that  they  be  made  by  someone  familiar  with  the  carbu- 


FIG.  113.— Carter  Model  C  carburetor. 

retor,  or  that  the  manufacturers'  instructions  be  followed  out  in  detail. 
The  common  carburetor  troubles  and  remedies  will  be  taken  up  in 
Chap.  IX. 

On  most  types  of  carburetors,  there  are  two  adjustments  to  be  made, 
a  low  speed  adjustment  and  a  high  speed  adjustment.  The  low  speed 
adjustment  is  made  with  the  engine  running  idle,  the  spark  retarded,  and 
the  throttle  about  one-quarter  open.  This  is  usually  the  gasoline  adjust- 
ment. The  high  speed,  or  auxiliary  air  adjustment,  is  made  with  the  en- 
gine running  with  throttle  open  and  spark  advanced.  In  all  cases  the 
adjustment  should  be  made  after  the  engine  has  warmed  up  to  its  normal 
running  temperature. 

Judging  the  mixture  is  largely  a  matter  of  experience.  A  rich  mixture 
is  indicated  by  the  overheating  of  the  cylinders,  waste  of  fuel,  choking 
of  the  engine  and  mis-firing  at  low  speeds,  and  by  a  heavy  black  exhaust 
smoke  with  a  very  disagreeable  odor.  A  weak  mixture  manifests  itself 
by  back-firing  through  the  carburetor  and  by  loss  of  power.  A  proper 
mixture  will  give  little  or  no  smoke  at  the  exhaust.  Blue  smoke  is  caused 
by  the  burning  of  excess  lubricating  oil  and  has  no  relation  to  the  quality 
of  the  mixture. 


FUELS  AND  CARBVRETTING  SYSTEMS 


99 


68.  Carburetor  Control  Methods.— The  carburetor  is  controlled  from 
the  driver's  seat.     The  hand  throttle  on  the  steering  post  regulates 
the  amount  of  mixture  to  the  cylinders,  thus  regulating  the  engine  and 
car  speed.     In  conjunction   with  the  throttle  connection,  is  the  ac- 
celerator on  the  toe-board,  which  permits  the  throttle  to  be  opened  by 
the  foot,  independently  of  the  hand  lever.     The  accelerator  must  be 
held  open  by  the  pressure  of  the  foot.     As  soon  as  pressure  is  removed 
from  it,  the  throttle  closes  to  the  point  set  by  the  hand  lever.     The  air 
and  gasoline  adjustments  are  usually  made  from  the  dash  of  the  car. 

69.  The  Gravity  Feed  System.— There  are  numerous  systems  for 
feeding  the  gasoline  to  the  carburetor  from  the  gasoline  tank,  which 
may  be  placed  at  tho  rear  of  the  frame,  in  the  cowl,  or  under  the  seat. 
These  feed  systems  are  classified  as  gravity,  pressure,  and  vacuum  systems. 


FIG.  114. — Studebaker  gravity  feed  system. 

In  the  gravity  system  of  gasoline  feed,  the  fuel  flows  to  the  carburetor 
by  gravity  alone.  The  tank  may  be  placed  either  under  the  seat  or  in  the 
cowl.  If  under  the  seat,  there  is  the  disadvantage  of  having  to  remove 
the  cushions  before  being  able  to  fill  the  tank.  There  is  also  the  possi- 
bility in  some  cases  that  the  tank  will  become  lower  than  the  carburetor 
when  going  up  hill,  and  consequently  the  gasoline  will  not  flow.  Both 
of  these  disadvantages  are  done  away  with  by  placing  the  tank  in  the 
cowl.  In  either  case,  however,  the  pressure  on  the  carburetor  float  valve 
varies  as  the  level  in  the  tank  varies.  When  filling  the  tank,  any  gaso- 
line which  spills  or  leaks  either  falls  around  the  seat,  in  the  car,  or  on  the 
engine.  The  advantage  of  the  gravity  system  is  that  it  is  simple  and 
always  ready.  Figure  114  shows  the  gravity  system  used  on  the  Stude- 


100  THE  GASOLINE  AUTOMOBILE 

baker  car,  with  the  tank  in  the  cowl.     This  shows  the  float  operating  the 
gasoline  indicator. 

70.  The  Pressure  Feed  System.— When  the  gasoline  tank  is  placed  at 
the  rear  of  the  frame,  it  is  obviously  impossible  to  use  the  gravity  system. 
By  putting  a  pressure  in  the  gasoline  tank,  the  gasoline  may  be  forced  by 
pressure  to  the  carburetor.  The  pressure  is  maintained  by  a  small  air 
pump  operated  by  the  engine,  or  by  a  hand  pump,  or  both.  After  filling 
the  tank,  a  hand  pump  is  used  to  get  up  pressure  until  the  engine  has 
been  started.  A  safety  valve  in  the  pressure  system  keeps  the  pressure 
from  getting  too  high.  A  particular  advantage  of  this  type  of  feed 


W..-SJ,, 


Shut.0«        G»olta. 


tor  Check' 

FIG.  115. — Pressure  feed  system. 


system  is  that  gasoline  feeds  to  the  carburetor  regardless  of  the  position 
of  the  car.  As  in  the  gravity  system,  the  pressure  on  the  float  valve  is 
liable  to  vary.  The  filler  cap  is  placed  away  from  the  engine  and  pas- 
sengers, and  gasoline  may  be  put  in  without  disturbance.  A  typical 
pressure  feed  system  is  illustrated  in  Fig.  115. 

71.  The  Vacuum  Feed  System. — Several  systems  have  been  developed 
in  which  the  gasoline  is  transferred  from  the  main  tank  at  the  rear  of  the 
car  by  vacuum,  or  suction,  to  a  small  auxiliary  tank  near  the  engine. 
From  this  small  tank  it  flows  by  gravity  to  the  carburetor.  Figures  116 
and  117  show  the  installation  of  the  Stewart  vacuum  system  in  a  car,  and 
Fig.  118  indicates  the  construction  of  the  auxiliary  vacuum  tank. 

This  system  comprises  a  small  round  tank,  mounted  on  the  engine 
side  of  dash.  This  tank  is  divided  into  two  chambers,  upper  and  lower. 
The  upper  chamber  is  connected  to  the  intake  manifold,  while  another 
pipe  connects  it  with  the  main  gasoline  tank.  The  lower  chamber  is 
connected  with  the  carburetor. 


FUELS  AND  CARBURETTING  SYSTEMS 


101 


The  intake  strokes  of  the  motor  create  a  vacuum  in  the  upper  cham- 
ber of  the  tank,  and  this  vacuum  draws  gasoline  from  the  supply  tank. 
As  the  gasoline  flows  into  this  upper  chamber,  it  raises  a  float  valve. 
When  this  float  valve  reaches  a  certain  height,  it  automatically  shuts 
off  the  vacuum  valve  and  opens  an  atmospheric  valve,  which  lets  the 
gasoline  flow  down  into  the  lower  chamber.  The  float  in  the  upper 


FIG.  116. — The  Stewart  vacuum  feed  system. 

chamber  drops  as  the  gasoline  flows  out,  and  when  it  reaches  a  certain 
point  it  in  turn  reopens  the  vacuum  valve,  and  the  process  of  refilling 
the  upper  chamber  begins  again.  The  same  processes  are  repeated 
continuously  and  automatically.  The  lower  chamber  is  always  open 
to  the  atmosphere,  so  that  the  gasoline  always  flows  to  the  carburetor 
as  required  and  with  an  even  pressure. 


FIG.  117. — Under   the  hood. — The   Stewart  vacuum   feed   system. 

The  amount  of  gasoline  always  remaining  in  the  tank  gets  some  heat 
from  the  motor  and  thereby  aids  carburetion;  it  also  makes  starting 
easier,  by  reason  of  supplying  warm  gasoline  to  the  carburetor.  The 
lower  chamber  of  the  tank  is  constructed  as  a  filter,  and  prevents  any 
water  or  sediment  that  may  be  in  the  gasoline  from  passing  into  the 
carburetor.  A  petcock,  in  the  bottom  of  the  tank,  permits  drawing  off 


102 


THE  GASOLINE  AUTOMOBILE 


this  sediment  and  also  allows  the  drawing  of  gasoline,  if  required  for 

priming  or  cleaning  purposes. 

72.  Intake  Manifolds.— The  tendency  in  present  engine  design  is 

to  make  the  intake  manifold  of  such  shape  and  proportions  that  the 
path  from  the  carburetor  to  the  engine  cylin- 
ders shall  be  as  short  and  smooth  as  possible. 
Being  close  to  the  cylinders,  the  manifold  as 
well  as  the  carburetor  is  heated,  greatly  aiding 
the  vaporization  of  the  gasoline.  The  short 
manifold  gives  the  gas  very  little  chance  to 
condense  between  the  carburetor  and  the 
cylinders.  It  is  also  desirable  to  have  the 
distance  from  the  carburetor  to  the  different 
cylinders  the  same  in  all  cases.  This  insures 
the  same  amount  of  mixture  to  each  cylinder. 
73.  Care  of  Gasoline. — Gasoline,  being  a 
volatile  liquid,  is  very  dangerous  if  not 
properly  handled,  but  if  proper  care  and  at- 
tention are  given  to  it  there  should  be  no 
danger  whatever.  It  should  never  be  ex- 
posed in  a  closed  room,  as  it  will  evaporate, 
mix  with  the  air,  and  form  a  very  explosive 
mixture.  Open  lights  should  always  be  kept 
away  from  gasoline  in  all  cases.  When  it  is 
necessary  to  handle  gasoline  at  night,  it 
should  be  done  with  an  electric  light.  Do 
not  under  any  conditions  use  an  open  light. 

In  putting  out  a  gasoline  fire,  water  will 
only  spread  the  fire,  as  the  gasoline,  being 
FIG.  118. — Stewart  vacuum   lighter  than  water,  floats  on  it.      The  only 
successful  method  of  extinguishing  a  gasoline 

fire  is  to  smother  it,  either  by  sand,  or  a  blanket,  or  by  the  gases  from  a 

fire  extinguisher. 

The  exhaust  gases  from  a  gasoline  engine  are  very  deadly.     Do  not 

breathe  them  for  any  length  of  time.     If  it  becomes  necessary  to  run 

your  engine  in  a  small  garage  with  the  doors  closed,  arrangement  should 

be  made  to  pipe  the  exhaust  to  the  outside  air. 


CHAPTER  V 
LUBRICATION  AND  COOLING 

74.  Friction  and  Lubricants. — The  purpose  of  lubrication  is  to  reduce 
friction  between  moving  surfaces.  If  parts  moving  on  each  other  were 
not  separated  by  a  film  of  lubricant,  the  surfaces  would  rapidly  rub 
away.  Friction  is  a  force  that  tends  to  retard  the  motion  of  one  surface 
over  another.  The  frictional  force  depends  on  the  nature  of  the  surface, 
and  also  on  the  kind  of  material.  It  is  caused  by  the  small  projecting 
particles  which  extend  from  the  surface.  The  rougher  the  surface  and 
the  softer  the  material,  the  greater  the  friction;  or,  the  harder  the  material 
and  the  smoother  the  surface,  the  less  the  friction.  The  more  friction 
there  is,  the  greater  the  loss  of  power,  as  it  requires  power  to  overcome 
friction.  A  great  amount  of  friction  is  necessary  in  certain  parts  of  the 
car  in  order  that  they  be  efficient,  such  as  in  the  brakes,  the  clutch,  and 
the  outer  surface  of  the  tires.  On  the  other  hand,  it  is  essential  that  all 
friction  possible  be  eliminated  from  the  bearings  in  order  to  have  as  little 
of  the  motive  power  lost  as  possible. 

The  principal  lubricants  used  are  fluid  oils,  semi-solids,  and  sometimes 
solids,  such  as  graphite.  There  are  three  general  sources  of  lubricants: 
animal  oils,  such  as  lard,  fish  oil,  etc.;  vegetable  oil,  such  as  olive  oil, 
linseed  oil,  etc.;  and  mineral  oils,  which  are  secured  from  petroleum. 
These  lubricating  mediums  should  each  be  used  where  they  are  best 
adapted.  An  oil  that  is  suitable  for  one  part  of  the  mechanism  may  not 
be  suited  for  another  part.  Only  mineral  oils  should  be  used  in  gasoline 
engine  cylinders,  as  they  alone  meet  the  requirements.  For  this  reason 
the  oils  used  for  steam  engine  cylinders  are  not  good  for  gasoline  engine 
use,  as  they  do  not  withstand  the  high  temperature  which  rises  in  the  gas 
engine  cylinder.  There  are  two  main  requirements  for  good  cylinder 
oil.  It  should  have  a  high  flash  point,  that  is,  it  should  not  break  down 
and  give  off  inflammable  gases  at  low  temperatures;  and,  second,  it 
should  retain  its  body  and  not  become  so  thin  as  to  be  worthless  as  a 
lubricant  at  high  temperatures.  It  should  have  sufficient  body  to 
maintain  a  positive  film  between  piston  and  cylinder,  yet  should  not  be 
so  heavy  as  to  retard  the  free  motion  of  the  piston  and  rings.  It  should 
also  be  free  from  acids  or  any  form  of  vegetable  or  animal  matter.  The 
vegetable  or  animal  matter  will  decompose  at  high  temperatures  and 
gum  up  the  cylinder.  The  acid  will  etch  the  smooth  surface  of  the 

103 


104  THE  GASOLINE  AUTOMOBILE 

cylinder  and  cause  excess  friction.  A  simple  method  to  test  for  acid  is 
to  dissolve  a  little  of  the  oil  in  warm  alcohol  and  then  dip  a  piece  of  blue 
litmus  paper  in  the  solution.  If  there  is  any  acid  present,  the  paper  will 
turn  red.  The  litmus  paper  can  be  obtained  at  any  drug  store. 

76.  Cylinder  Oils. — Cylinder  oils  are  usually  classified  in  three 
grades;  light,  medium,  and  heavy.  Light  cylinder  oil  looks  something 
like  the  ordinary  machine  oil,  and  is  slightly  more  viscous.  The  medium 
is  somewhat  heavier  than  the  light,  and  might  be  compared  to  warm 
maple  syrup.  Light  and  medium  oils  should  be  used  only  on  engines 
which  have  close-fitting  pistons.  The  heavy  oil  is  used  in  air-cooled 
engines  and  in  engines  that  have  loose  pistons  or  that  become  too  hot 
to  use  the  lighter  grade  of  oil.  A  good  gas  engine  oil  should  have  a 
high  degree  of  viscosity  at  100°F.,  a  flash  point  not  under  400°,  and  a  fire 
test  of  over  500°. 

76.  Viscosity. — Viscosity  is  the  property  of  a  liquid  by  which  it  has  a 
tendency  to  resist  flowing.     Oils  are  tested  for  viscosity  by  being  put  in  a 
container  and  allowed  to  flow  through  a  small  opening.     The  oil  that 
flows  the  fastest  has  the  least  viscosity.     In  some  parts  of  the  automobile 
it  is  necessary  to  use  oil  with  less  viscosity  than  in  other  parts.     Tight 
fitting  bearings  should  use  oil  with  very  little  viscosity,  while  meshed 
gears  should  have  semi-solid  lubricants  because  the  pressure  on   the 
rubbing  surfaces  is  very  high. 

77.  Flash  Point.^-The  flash  point  is  the  temperature  at  which,  if  an 
oil  be  heated  and  a  flame  held  over  the  surface,  the- vapor  rising  from  the 
oil  will  burst  into  flame,  but  will  not  continue  to  burn.     A  thermometer 
is  placed  in  the  oil  bath  and  the  temperature  taken  at  this  point. 

78.  Fire  Test  and  Cold  Test. — Fire  test  is  merely  a  continuation  of  the 
flash  point  test;  that  is,  the  temperature  at  which  the  vapor  which  rises 
from  the  oil  will  continue  burning,  and  not  merely  flash  for  a  second. 
Both  these  tests  are  used  only  on  cylinder  oil. 

There  is  another  test  that  is  called  the  "cold  test,"  which  indicates 
the  temperature  at  which  the  oil  hardens,  or  becomes  so  stiff  as  not  to 
flow.  Good  cylinder  oil  should  not  become  so  stiff  as  to  prevent  reaching 
the  desired  points  at  zero  temperature. 

79.  General  Notes  on  Lubrication. — There  is  no  one  thing  which  is 
the  primary  cause  of   more  trouble  and   the   cause   of   more   expense 
in  maintenance   to  the  mechanism  of   an  automobile  than  insufficient 
lubrication. 

All  moving  parts  of  a  car  are  usually  manufactured  with  a  high  degree 
of  accuracy  and  the  parts  are  carefully  assembled.  In  order  to  maintain 
the  running  qualities  of  the  car  it  becomes  necessary  to  introduce  sys- 
tematically suitable  lubricants  between  all  surfaces  which  move  in  con- 
tact with  one  another. 


LUBRICATION  AND  COOLING  105 

The  special  object  of  this  chapter  is  to  point  out  the  places  in  the  car 
which  require  oiling.  While  it  is  manifestly  impossible  to  give  exact 
instructions  in  every  instance  as  to  just  how  frequently  each  individual 
point  should  be  oiled  or  exactly  how  much  lubricant  should  be  applied, 
we  can  give  this  approximately,  based  on  average  use. 

It  should  be  borne  in  mind  that  friction  is  created  wherever  one 
part  moves  upon  or  in  contact  with  another.  Friction  means  wear,  and 
the  wear  will  be  of  the  metal  itself  unless  there  is  oil,  and  oil  is  much 
cheaper  than  metal.  The  use  of  too  much  oil  is  better  than  too  little, 
but  just  enough  is  best. 

Proper  lubrication  not  only  largely  prevents  the  wearing  of  the  parts, 
but  it  makes  the  car  run  more  easily,  consequently  with  less  expense  for 
fuel  and  makes  its  operation  easier  in  every  way. 

The  oiling  charts  shown  in  this  chapter  indicate  the  more  important 
points  which  require  attention.  But  do  not  stop  at  these.  Notice  the 
numerous  little  places  where  there  are  moving  parts,  such  as  the  yokes 
on  the  ends  of  various  connecting  rods,  and  pull  rods,  etc.  A  few  drops 
of  oil  on  these  occasionally  will  make  them  work  more  smoothly. 

Oil  holes  sometimes  become  stopped  up  with  dirt  or  grease.  When 
they  do,  clean  them  out  and  be  careful  not  to  overlook  them.  Also  be 
careful  not  to  allow  dirt  or  grit  to  get  into  any  bearings. 

Judicious  lubrication  is  one  of  the  greatest  essentials  to  the  satisfac- 
tory running  and  the  long  life  of  the  motor  car.  Therefore  lubricate,  and 
lubricate  judiciously.' 

The  auto  engine  should  be  lubricated  by  some  means  that  will  insure 
a  definite  supply  of  lubricant  to  the  moving  parts  and  that  will  supply 
the  loss  caused  from  vaporizing,  burning  and  leakage. 

The  differential,  axle  bearings  and  shift  gears  are  lubricated  with  semi- 
solid  grease.  The  rear  axle  is  not  oil-tight,  and  therefore  a  fluid  oil 
should  not  be  used.  Semi-solid  lubricants  also  help  to  cut  down  the 
noise  and  wear  where  the  pressure  is  heavy,  and  have  sufficient  cushion  so 
that  they  adhere  to  the  gear  teeth.  The  lighter  oils  are  better  adapted 
for  the  high  speed  close-fitting  parts.  Other  moving  parts  may  be 
lubricated  with  the  ordinary  oil  can,  but  are  generally  lubricated  by  the 
compression  cup  system.  These  cups  may  be  screwed  up  from  time  to 
time  to  add  more  lubricant  to  the  bearing  surfaces. 

The  transmission  should  always  contain  sufficient  lubrication  to  bring 
it  up  to  the  level  of  the  drain  plug  on  the  side  of  the  case,  or  so  that  the 
under  teeth  of  the  smallest  gear  will  enter  to  their  full  depth. 

The  differential  case  should  contain  enough  lubricant  to  bring  it  up 
to  the  filling  hole,  or  should  be  about  one-third  full. 

Wheel  bearings  should  be  packed  with  a  thin  cup  grease.  Do  not 
use  a  heavy  grease  because  it  will  work  away  from  the  path  of  the  roller 


106  THE  GASOLINE  AUTOMOBILE 

or  ball  and  will  not  return.  In  each  hub  there  is  usually  a  small  oil  hole. 
Inject  some  engine  oil  here  whenever  you  are  oiling  the  car.  It  will  keep 
the  grease  soft  and  in  good  condition.  Before  lubricating  any  part, 
wipe  all  dirt  from  it  so  that  the  dirt  will  not  get  into  the  bearings. 

The  steering  gear  is  perhaps  one  of  the  most  important  parts  of  the 
car  to  keep  properly  lubricated.  Failure  of  the  steering  apparatus  is  a 
dangerous  thing  and  a  few  drops  of  oil  given  to  the  oil  cups  and  the 
various  steering  connections  constitute  a  cheap  and  safe  means  of  avoid- 
ing accidents.  Most  types  of  steering  apparatus  are  packed  with  grease 
which,  having  no  outlet,  will  remain.  However,  the  grease  will  become 
dry  and  a  little  oil  should  be  added  from  time  to  time. 

Few  motorists  think  of  lubricating  their  brake  connections.  Mud 
and  water  will  find  their  way  into  the  brake  mechanism  and  a  squeeze  of 
the  oil  can  and  a  turn  of  the  grease  cups,  given  daily  will  keep  them  in 
good  working  condition. 

The  principal  engine  lubricating  systems  can  be  grouped  under  the 
following  heads:  first,  splash  system;  second,  splash  with  circulating 
pump,  which  maybe  either  a  "forced  feed"  or  a  "pump-over"  system; 
third,  full  forced  feed;  fourth,  mixing  the  oil  with  the  gasoline. 

80.  Splash  System  of  Engine  Lubrication. — The  splash  system  is  used 
in  the  Ford  engine,  as  shown  in  Fig.  119.     The  oil  is  poured  directly  into 
the  crank  case  until  it  comes  above  the  lower  oil  cock.     The  level  of  the 
oil  should  be  maintained  somewhere  between  the  two  oil  cocks.     The 
flywheel  runs  in  the  oil  and  picks  up  some  of  it  and  throws  it  off  by  cen- 
trifugal force;  some  of  the  oil  is  caught  in  a  tube  and  carried  to  the  front 
end  of  the  crank  case  where  it  lubricates  the  timing  gears.     As  the  oil 
flows  back  to  the  rear  part  of  the  crank  case,  it  fills  the  small  wells  in  the 
crank  case  under  each  connecting  rod.     As  the  connecting  rod  comes 
around,  a  small  spoon  or  dipper  on  the  bottom  scoops  up  the  oil,  so  that 
there  is  a  regular   shower   of  oil  all  the  time.     The  pistons,  cylinder 
walls,  and  bearings  are  lubricated  in  this  manner  and  the  oil  is  kept  in 
continuous  circulation.     All  parts  of  the  clutch  and  transmission  are 
lubricated  in  the  same  manner  as  the  engine. 

The  oil  level  should  never  get  below  the  lower  oil  cock  and  should 
never  get  above  the  upper  oil  cock.  Never  test  the  level  of  the  oil  when 
the  engine  is  running. 

81.  Splash  System  with  Circulating  Pump. — This  system  has  an  oil 
reservoir  or  sump  below  the  main  crank  case  bottom.     The  oil  from 
the  sump  in  the  lower  half  of  the  crank  case  is  sucked  through  a  strainer 
into  the  pump,  usually  at  the  rear  end  of  the  reservoir.     The  oil  pump 
of  the  Buick  engine  is  shown  in  Fig.  120.     This  pumps  the  oil  up  through 
a  pipe  to  a  sight  feed  on  the  dash  so  that  the  circulation  can  be  observed 
by  the  driver.     From  here  the  oil  returns  to  the  splash  trays  in  the  lower 


LUBRICATION  AND  COOLING 


108 


THE  GASOLINE  AUTOMOBILE 


half  of  the  crank-case  through  the  distributor  pipe.  As  the  crank  comes 
around,  the  spoons  or  dippers  on  the  connecting  rods  dip  into  these 
trays  and  force  some  of  the  oil  up  into  the  crank  pin  bearings  and  splash 
the  remainder  over  the  interior  of  the  crank  case  and  up  into  the  cylinders 
and  pistons.  As  the  oil  drains  back,  it  is  caught  in  ducts  and  led  to  all 
the  bearings  of  the  motor,  the  excess  running  back  into  the  sump  to  be 
used  again. 

The  oil  circulating  pump  consists  of  two  small  gears  enclosed  in  a 
close  fitting  housing  attached  to  the  lower  half  of  the  crank  case  and 

driven  by  a  vertical  shaft  and  spiral 
gears  from  the  cam  shaft.  As  the  gears 
turn,  they  take  the  oil  into  the  spaces 
between  the  teeth  and  carry  it  around 
to  the  outlet  where  the  action  of  the 
teeth  meshing  together  squeezes  the  oil 
out  of  the  spaces  and  forces  it  to  flow  to 
the  sight  feed  on  the  dash.  The  pump 
requires  no  attention  or  adjustment  ex- 
cept the  addition  of  fresh  oil  to  the 
crank  case  reservoir  as  often  as  is 
necessary  to  keep  the  oil  level  up  to  the 
oil  cock.  The  sight  feed  on  the  dash 
merely  shows  whether  or  not  the  oil  is 
circulating  and  does  not  show  when  the 
supply  in  the  crank  case  is  running  low. 
Test  the  oil  level  at  frequent  intervals 
by  opening  the  oil  cock  and  see  that  the 
oil  is  kept  up  to  this  level.  To  remove 
the  pump,  draw  off  all  the  oil  and  take 
the  pump  out  from  below. 

The  motor  lubrication  on  the  Overland  car  is  shown  in  Fig.  121,  ' 
and  is  the  splash  and  pump-over  system.  The  oil  reservoir  is  located 
m  the  bottom  of  the  crank  case  and  is  filled  through  the  combination 
breather  pipe  and  oil  filler  on  the  right  side  of  the  engine.  The  glass 
gauge  on  the  side  of  the  crank  case  close  to  the  breather  pipe  indicates  the 
oil  level.  The  oil  pump,  which  is  located  in  the  rear  of  the  crank  case,  is 
driven  from  the  cam  shaft.  The  lubricant  is  drawn  from  the  base  and, 
after  passing  through  a  strainer,  runs  through  a  sight  feed  on  the  dash, 
and  from  there  it  runs  into  the  troughs  and  is  splashed  into  the  bearing 
surfaces.  It  is  very  important  that  the  oil  strainer  be  kept  clean  at  all 
;imes  so  that  proper  circulation  of  the 'oil  is  insured.  For  this  reason 
B  removal  of  the  oil  strainer  has  been  made  easy.  By  unscrewing  the 
large  plug  on  the  side  of  the  crank  case  right  opposite  the  oil  pump,  the 


FIG.  120, — Buick  oil  pump. 


LUBRICATION  AND  COOLING 


109 


cylindrical  screen  may  be  drawn  out 'and  cleaned  by  dipping  into  a  pail 
of  gasoline.  The^  owner  should  see  that  the  oil  screen  is  cleaned  every 
200  miles  of  the  first  1000  miles  and  after  that  every  500  miles. 

The  lubricant  circulates  freely  through  the  system  as  long  as  the  small 
wheel  in  the  dash  sight-feed  revolves.  But  as  soon  as  the  wheel  stops 
or  the  sight-feed  glass  shows  clear,  this  is  an  indication  that  the  oil  supply 
is  exhausted,  or  that  there  is  an  obstruction  in  the  circulation  of  the 
oil  which  should  be  located  and  remedied  immediately,  since  serious 
and  expensive  trouble  will  result  from  running  the  motor  with  an  in- 
sufficient supply  of  oil. 


FIG.  121. — Overland    splash    system    with    circulating    pump. 

The  wrist  pin  is  lubricated  from  the  cylinder  walls,  through  the 
opening  in  the  piston  through  which  the  wrist  pin  is  inserted,  as  well  as 
through  a  slot  cut  into  the  connecting  rod  over  the  wrist  pin  bushing. 

The  lubrication  system  of  the  Studebaker  Four,  Fig.  122,  is  called 
the  constant  level  splash  system  combined  with  a  forced  feed  to.  the 
timing  gears.  A  quantity  of  oil  is  carried  in  a  reservoir  F,  which  is 
formed  by  the  crank  case  of  the  motor.  A  pump  B  of  the  plunger  type 
draws  the  oil  from  this  reservoir  and  sprays  it  (G)  over  the  connecting 
rod  bearings.  It  also  pumps  surplus  oil  through  a  sight  feed  J  or  indi- 
cator on  the  dash,  from  which  it  flows  over  the  timing  gears  D  at  the 


110 


THE  GASOLINE  AUTOMOBILE 


front  of  the  motor  and  returns  to  the  reservoir  through  the  pipe  U. 
The  oil  draining  from  the  spray  collects  in  troughs  E  which  maintain  a 
constant  level  of  oil  just  under  the  connecting  rods.  At  each  revolu- 
tion short  projections  M  from  the  connecting  rods  dip  into  these  troughs 
and  splash  oil  over  the  lower  ends  of  the  pistons,  and  over  the  cam  and 
crank  shaft  bearings. 

To  fill  the  oil  reservoir  of  the  motor,  pour  the  oil  in  through  a  funnel 
shaped  tube  H,  which  you  find  on  the  left  side  of  the  motor.  This 
funnel  shaped  tube  is  called  the  "breather  pipe."  At  the  side  of  the 
"breather  pipe"  there  is  a  gauge  /  which  shows  the  amount  of  oil  in  the 


FIG.  122. — Studebaker   splash   system   with   forced   feed. 

reservoir.  The'  oil  is  poured  into  the  breather  pipe  until  the  gauge 
indicator  rises  to  the  highest  point  of  the  gauge,  being  careful  that  there 
is  no  more  oil  poured  into  the  motor  than  just  enough  to  bring  the  in- 
dicator to  the  highest  point  shown  on  the  gauge.  The  only  attention 
necessary  to  keep  the  motor  perfectly  lubricated  is  to  see  that  the  gauge 
indicator  shows  that  there  is  oil  in  the  reservoir. 

When  the  motor  is  running,  oil  drops  through  a  glass  indicator  or 
"sight  feed"  J  on  the  dash.  This  "sight  feed"  can  be  seen  from  the 
seat. and  should  not  be  forgotten  by  the  driver.  If  the  oil  should  cease 
to  flow  through  the  "sight  feed"  when  the  motor  is  running,  the  motor 
should  be  stopped  and  hood  lifted  to  ascertain  if  the  gauge  I  shows 
oil  in  the  reservoir.  If  it  does  show  oil  in  the  reservoir,  then  either  the 
oil  pump  or  the  connecting  oil  pipes  are  clogged  and  should  be  cleaned 
out. 


LUBRICATION  AND  COOLING 


111 


82.  Full  Forced  Feed  System. — A  full  forced  feed  as  used  on  the 
Cadillac  Eight  is  shown  in  Fig.  123.  A  gear  pump  located  at  the  for- 
ward end  of  the  motor  and  driven  from  the  crank  shaft  takes  the  oil  up 
from  the  oil  pan  in  the  lower  part  of  the  crank  case  and  forces  it  through 
a  reservoir  pipe  running  along  the  inside  of  the  crank  case,  from  which 
pipe  there  are  leads  to  each  of  the  main  bearings.  The  crank  shaft  and 
webs  are  drilled  and  oil  is  forced  from  these  main  bearings  to  the  con- 
necting rod  bearings  through  the  drilled  holes.  The  forward  and  rear 
bearings  supply  the  rod  bearings  nearest  them,  while  the  center  bearing 


PBESSURE  GAUGE 
ON  DASH' 
ADJUSTABLE 
PEESSUI2E 
VALVI 


FIG.  123. — Cadillac    forced    feed    oiling    system. 

takes  care  of  the  rod  bearings  on  either  side  of  it.  The  oil  is  then  forced 
from  the  main  reservoir  pipe  up  to  the  relief  valve,  which  maintains  a 
uniform  pressure  above  certain  speeds,  and  overflows  from  this  valve  to 
a  pipe  extending  parallel  with  the  cam  shaft  and  above  it.  Leads  from 
this  latter  pipe  carry  lubricant  by  gravity  to  the  cam  shaft  bearings  and 
front  end  chains.  Pistons,  cylinders  and  piston  pins  get  their  oiling  by 
the  oil  thrown  from  the  lower  ends  of  the  connecting  rods. 

A  gauge  indicating  the  level  of  the  oil  is  attached  to  the  upper  cover 
of  the  crank  case.  Whenever  the  indicator  reaches  the  space  marked 
"fill,"  oil  should  be  added  until  the  indicator  returns  to  "full."  A  filling 
hole  is  provided  in  each  block  between  the  second  and  third  cylinders. 
If  the  hand  on  the  pressure  gauge  on  the  cowl  vibrates  or  returns  to  zero 
on  the  dial  when  the  engine  is  running,  it  indicates  that  the  oil  level  is  very 


H2  THE  GASOLINE  AUTOMOBILE 

low.     Should  this  occur  through  neglect  to  add  oil  at  the  proper  time,  the 

engine  should  immediately  be  stopped  and  sufficient  oil  added  to  bring 

the  pointer  up  to  the  top  of  the  gauge  before  the  engine  is  again  started. 

The  hollow  crank  shaft  oiling  system  as  used  by  the  Wisconsin  Motor 

Mfg.  Co.  is  shown  in  Fig.  124  and 
operates  as  follows: 

The  oil  is  carried  in  an  inde- 
pendent chamber  at  the  bottom 
of  the  crank  case,  and  the  con- 
necting rods  are  not  allowed  to  dip 
into  this,  thus  preventing  the  oil 
from  being  whipped  to  a  froth, 
and  preserving  its  viscosity. 

It  is  pumped  by  means  of  a 
gear  pump  located  at  the  lowest 
point  of  the  oil  reservoir  into  a 
main  duct,  which  is  cast  integral 
with  the  crank  case,  and  from  here 
distributed  by  means  of  ducts, 
drilled  into  the  webs,  to  the  main 
bearings.  From  here  it  is  forced 
through  a  hollow  crank  shaft  to 
the  connecting  rod  bearings,  and  a 
sufficient  amount  of  oil  is  forced 
out  of  the  ends  of  the  bearings  to 
lubricate  the  pistons,  piston  pins, 
and  cam  shafts.  A  separate  lead 
runs  directly  over  the  timing  gears, 
and  all  oil  is  thoroughly  filtered 
before  it  is  pumped  over  again. 
An  oil  gauge  indicates  by  means  of 
a  ball  and  float  the  exact  amount 
of  oil  contained  in  the  reservoir, 
and  distinct  marks  on  the  glass 
gauge  show  the  high  and  low  mark, 
and  if  the  oil  is  maintained  be- 
tween these  two  levels  no  burnt 
oil  smoke  will  be  emitted,  and  the 
spark  plugs  will  not  be  fouled. 

The  pressure  of  the  oil  increases  with  the  speed  of  the  motor,  so  the 
faster  the  motor  is  run  the  more  oil  is  forced  to  it,  and  vice  versa.  The 
location  of  the  oil  reservoir  permits  the  proper  cooling  of  the  oil,  thus 
minimizing  the  danger  of  burning  out  bearings. 


LUBRICATION  AND  COOLING  113 

The  lubricating  system  for  Knight  sliding  sleeve  motors  is  also  of  the 
forced  feed  type.  The  following  description  is  of  the  system  used  on  the 
Moline-Knight  car.  Oil  is  drawn  from  the  sump  by  a  gear  pump  driven 
off  the  end  of  the  eccentric  shaft,  and  is  delivered  to  the  three  main  bear- 
ings, and  the  magneto  drive  shaft  bearing  under  a  pressure  determined 
by  the  settings  of  a  spring  controlled  by-pass  valve,  through  which  the 
excess  oil  is  delivered.  This  excess  oil  is  led  to  the  chain  driving  the 
eccentric  shaft  and  magneto,  and  flows  thence  to  a  trough  and  through  a 
screen  to  the  sump.  Part  of  the  oil  delivered  to  the  main  bearings  passes 
through  holes  in  the  crank  shaft  web  to  the  crank  pins,  and  thence  through 
the  tubular  connecting  rod  to  the  hollow  piston  pins.  From  the  two 
ends  of  the  latter  it  flows  to  the  sleeves  and  is  distributed  through  holes 
and  oil  grooves  in  the  latter  over  their  circumference  and  the  cylinder 
walls.  All  parts  requiring  lubrication  not  mentioned  above  are  oiled 
by  splash  from  the  crank  shaft  and  connecting  rods.  The  flow  of  oil 
delivered  under  pressure  is  determined  by  a  valve  which  is  so  connected 
as  to  open  and  close  with  the  throttle.  There  are  no  oil  grooves  in  any  of 
the  crank  shaft  bearings.  The  entire  bottom  of  the  crank  case  is  covered 
by  a  screen,  through  which  the  oil  returns  to  the  sump. 

83.  Mixing  the  Oil  with  the  Gasoline. — Another  system  that  is  used 
to  some  extent  in  two-stroke  marine  engines  is  to  mix  the  lubricating  oil 
with  the  gasoline,  in  the  proportion  of  1  pt.  of  oil  to  5  gal.  of  gasoline. 
The  easiest  way  is  to  thoroughly  mix  1  pt.  of  oil  with  1  gal.  of  gasoline, 
pour  it  into  the  fuel  tank  and  then  add  4  gal.  of  gasoline.     The  oil  stays 
in  solution  with  the  gasoline.     This  system  is  very  simple,  as  the  lubri- 
cating becomes  automatic  and  there  are  no  regulators  to  adjust. 

When  the  piston  is  on  the  up  stroke,  a  charge  of  gasoline  and  oil  is 
drawn  through  the  carburetor.  Here  the  oil  and  gasoline  separate 
because  the  oil  does  not  evaporate  and  the  gasoline  does.  The  gasoline 
mixes  with  the  air  in  the  form  of  a  gas.  The  oil  collects  in  the  form 
of  small  globules  which  float  in  the  mixture  of  gas  and  air  and  are  carried 
into  the  crank  case  by  the  suction  of  the  motor.  Here  some  of  the  oil 
settles  on  the  connecting  rod  and  crank  and  flows  through  a  special  oil 
duct  to  the  crank  pin. 

On  the  down  stroke  of  the  piston,  the  gas  and  oil  are  forced  through 
the  by-pass  into  the  cylinder  where  the  remainder  of  the  oil  is  deposited 
on  the  cylinder  walls.  This  operation'  is  repeated  every  revolution  of 
the  engine,  a  new  film  of  oil  being  supplied  each  time. 

84.  Selection  of  a  Lubricant. — The  proper  lubrication  of  the  motor 
car  is  more  important  than  any  other  item  in  its  care.     Only  the  best 
high  grade  oils  should  be  used  to  lubricate  the  engine.     Some  engines 
require  lighter  oils  than  others  on  account  of  the  close-fitting  pistons  and 
rings.     It  is  better  to  follow  the  instructions  sent  out  by  the  manufac- 


114  THE  GASOLINE  AUTOMOBILE 

turers  in  regard  to  the  kind  of  oil  to  use  rather  than  for  the  motorist  to 
make  his  choice  or  to  be  directed  by  an  oil  salesman.  The  different  com- 
panies run  extensive  tests  and  find  out  in  that  way  which  oil  is  best  suited 
for  their  type  of  engine.  The  only  way  to  get  the  best  lubricants  is  to  pay 
the  price.  Money  saved  by  cheap  oils  or  grease  may  be  more  than  lost 
in  worn-out  bearings  or  cylinders. 

The  multiple-disc  type  of  clutch  is  the  only  one  in  which  any  lubrica- 
tion should  be  used,  and  the  oil  here  should  be  drained  off  about  every 
1000  miles,  the  clutch  well  cleaned  out  with  kerosene,  and  then  filled  with 
light  machine  oil,  the  amount,  of  course,  depending  upon  the  capacity 
of  the  case.  All  clutches  that  use  any  kind  of  facing,  such  as  asbestos, 
raybestos,  or  leather,  should  never  be  lubricated,  as  the  oil  decreases  the 
friction  and  causes  slipping.  Clutch  leathers  will  retain  their  life  and 
softness  better  if  given  an  occasional  treatment  of  neatsfoot  oil  and  then 
wiped  dry. 

The  planetary  transmission  system  in  the  Ford  automobile  is  encased 
so  as  to  revolve  in  an  oil  bath. 

The  differential  housing  and  sliding  gear  transmissions  and  all  other 
parts  that  use  either  heavy  cylinder  oil,  transmission  oil,  or  graphite 
grease,  should  be  thoroughly  cleaned  every  1000  miles,  or  thereabouts, 
and  well  flushed  out  with  kerosene  in  order  to  remove  all  sediment  and 
metallic  dust  that  may  be  in  the  old  grease.  All  wheel  bearings  are  of 
the  ball  or  roller  anti-friction  type,  and  are  packed  with  semi-fluid 
grease  which  should  be  renewed  about  every  1000  miles. 

An  excess  of  grease  in  the  transmission  or  differential  case  will  be  shown 
by  leaking  at  the  joints,  on  account  of  the  difficulty  of  keeping  these 
members  absolutely  tight  and  still  free  to  run.  If  there  is  too  much 
grease  in  the  differential  case,  it  will  run  along  the  axle  shaft  and  out  over 
the  oil  guard,  which  is  to  prevent  it  from  getting  on  the  tire  and  also  from 
interfering  with  the  action  of  the  internal  brake. 

Excess  of  lubrication  in  the  engine  will  produce  carbon  deposits  and 
dirty  spark  plugs.  It  may  also  cause  the  piston  rings  to  gum  up  and  stick. 
It  can  be  detected  by  the  color  of  the  exhaust  smoke,  which  will  have  a 
bluish  tinge,  or  it  may  be  detected  by  a  sticky  black  coating  on  the  spark 
plug. 

A  small  amount  of  graphite  and  oil  or  grease  should  be  supplied  be- 
tween the  leaves  of  the  springs.  This  can  generally  be  done  by  jacking 
up  the  frame  so  that  all  weight  is  taken  off  the  wheels,  and  by  using 
a  small  clamping  device  with  wedge-shaped  jaws,  which  can  be  used  to 
spread  the  leaves  apart. 

85.  Directions  for  Lubrication.— A  very  good  chart  for  lubrication 
purposes  is  sent  out  by  the  Chalmers  Motor  Car  Co.,  and  of  course  can 
be  used  for  other  standard  makes  of  cars.  This  chart  is  as  follows: 


LUBRICATION  AND  COOLING 


115 


DIRECTIONS  FOR  LUBRICATION 


EVEBT  DAY  CAB  is  IN  USE,  OB  EVEBY  100  MILES: 


Part 

Crank  case. 

Steering  knuckle  grease  cups. 
Steering  cross  rod  grease  cups. 
All  spring  bolt  grease  cups. 
Speedometer  driving  gears. 
Eccentric  bushing  of  steering  gear. 
Wheel  hub  oilers. 


Quantity 

Keep  oil  at  level  of  top  try  cock. 
One  complete  turn. 
One  complete  turn. 
Two  complete  turns. 
One  complete  turn. 
10  or  15  drops. 
10  drops. 


TWICE  A  WEEK,  OB  ABOUT  EVEBY  200  MILES: 

Part  Quantity 

Fan  hub  bearing.  Few  drops. 

Pump  shaft  grease  cups.  Two  complete  turns. 

Steering  gear  case  oiler.  Fill. 

Steering  gear  case  grease  cup.  Two  complete  turns. 

Steering  wheel  oil  hole.  8  or  10  drops. 

Steering  column.  10  or  15  drops. 

EVEBY  WEEK,  OB  ABOUT  EVEBY  300  MILES: 


Part 

Spark  and  throttle  shafts. 

Control  bracket  bearings. 

Transmission  case. 

Pedal  fulcrum  pin. 

Brake  pull  rods  and  connections. 

Brake  cross  rod  grease  cups. 

Torque  rod  grease  cups,  front  and  rear. 

Brake  shafts  on  rear  wheels. 

Rear  spring  perch  grease  cups. 


Quantity 
Few  drops. 
Thoroughly. 

Enough  to  cover  lower  shaft. 
Thoroughly. 
Thoroughly. 
Two  complete  turns. 
Two  complete  turns. 
Thoroughly. 
Two  complete  turns. 


TWICE  A  MONTH,  OB  EVERY  500  MILES: 

Part  Quantity 

Magneto  bearings  (3  oil  holes).  3  or  4  drops  each. 

Dynamo  drive  shaft  universal  joints.        Fill  one-half  full. 
EVEBY  MONTH,  OB  EVERY  1000  MILES: 


Lubricant 
Motor  oil. 
Cup  grease. 
Cup  grease. 
Cup  grease. 
Cup  grease. 
Motor  oil. 
Motor  oil. 

Lubricant 
Motor  oil. 
Cup  grease. 
Motor  oil. 
Cup  grease. 
Motor  oil. 
Motor  oil. 

Lubricant 
Motor  oil. 
Motor  oil. 
Motor  oil. 
Motor  oil. 
Motor  oil. 
Cup  grease. 
Cup  grease. 
Motor  oil. 
Cup  grease. 

Lubricant 

High   grade  light   ma- 
chine oil. 
Cup  grease. 


Part 
Crank  case. 


Reach  rod  boots. 

Spring  leaves.     (Jack   up  frame   and 

pry  leaves  apart.) 
Hub  caps. 
Universal  joints. 

Gasoline  pressure  hand  pump. 


Quantity 
Drain  off  dirty  oil;  clean  oil  screen  at 

left  of    motor  thoroughly;   fill  to 

level  of  top  try  cock. 
Pack  thoroughly. 
Thoroughly. 

Pack  thoroughly. 

Remove  grease  hole  plug  and  fill  one- 
half  full. 
4  or  5  drops  on  leather  plunger. 


Lubricant 
Motor  oil. 


Cur 

Graphite  grease. 


Cup  grease. 
Cup  grease. 


Light  machine  oil. 


EVEBY  2000  MILES: 

Part 

Differential  housing. 
Transmission  case. 


Quantity 

3pt. 

Drain  thoroughly,  flush  with  kero- 
sene, refill  to  cover  top  lower 
shaft  try  cock. 


Lubricant 

Special  axle  compound. 
Motor  oil.1 


Dynamo  should  be  lubricated  every  3000  to  5000  miles. 

When  changing  tires,  put  a  few  drops  of  oil  on  inside  sliding  ring  of  demountable  rims  to  insure  easy 
detaching. 


116 


THE  GASOLINE  AUTOMOBILE 


QREAiftg 


LUBRICATION  AND  COOLING  117 

Figure  125  shows  the  location  of  the  various  places  to  be  lubricated 
and  the  proper  intervals  for  lubrication.  This  is  the  chart  for  the  Case 
car. 

86.  Cylinder  Cooling. — When  an  explosion  occurs  inside  the  cylinder 
of  a  gas  engine,  the  gases  on  the  inside  reach  a  temperature  of  from  2000° 
to  3000°F.     The  walls  of  the  cylinder  are,  of  course,  exposed  to  this  high 
heat  and  would  very  quickly  get  red  hot  if  we  did  not  have  some  way  of 
keeping  them  cool.     The  polished  surface  upon  which  the  piston  slides 
would  be  very  quickly  spoiled.     The  most  common  way  of  keeping  a 
cylinder  cool  is  by  the  use  of  water.     Surrounding  the  cylinder  is  a  metal 
jacket  enclosing  a  space  for  the  cooling  water.     By  keeping  a  supply  of 
water  passing  through  this  space,  the  cylinder  can  be  kept  cool  enough 
for  the  operation  of  the  engine.     The  cylinder  head  is  also  cast  with  a 
double  wall,  especially  around  the  valves,  so  that  these  parts  will  also  be 
kept  cool.     The  cooling  fluid  used  is  generally  water. 

Water  should  not  be  allowed  to  remain  in  the  jacket  of  an  engine  over 
night  if  there  is  danger  of  a  frost,  as  the  freezing  of  the  water  will  crack  the 
cylinder.  When  the  supply  of  water  is  limited,  as  in  an  automobile, 
the  water  is  cooled  in  a  radiator  or  system  of  pipes,  and  then  is  used  over 
again.  The  water  is  kept  in  circulation  by  a  pump,  or  by  the  thermo- 
syphon  system,  and  the  hot  water  is  cooled  by  the  air  passing  over  the 
radiator. 

The  circulation  in  the  thermo-syphon  system  is  based  on  the  fact  that 
cold  water  is  heavier  than  hot  water,  and  consequently,  the  water  heated 
in  the  cylinder  jackets  flows  up  and  over  into  the  top  part  of  the  radiator, 
where  it  is  cooled  and  then  flows  from  the  lower  portion  of  the  radiator 
back  to  the  engine  cylinder.  Circulation  is  automatically  maintained  as 
long  as  the  engine  is  hot  and  there  is  enough  water  in  the  radiator  so  that 
the  return  connection  from  the  cylinder  to  the  radiator  contains  water. 
This  means  that  the  radiator  must  be  kept  practically  full  all  the  time,  or 
else  there  will  be  no  circulation  and  the  water  will  merely  boil  away. 

When  the  pump  system  of  circulation  is  used,  the  radiator  may  be 
lighter  than  in  the  syphon  system,  as  less  water  is  needed  to  do  the  same 
amount  of  cooling.  The  pump  is  driven  from  the  engine,  and  the  faster 
the  motor  runs  the  faster  the  water  circulates.  The  centrifugal  type  of 
pump  is  generally  used  for  circulating  cooling  water. 

87.  Water  Cooling  Systems. — Radiators  differ  in  design.     In  some 
types  the  water  flows  through  tubes  of  very  small  diameter.     In  this 
type  it  is  necessary  to  have  a  circulating  pump  of  some  kind.     In  radia- 
tors having  tubes  of  larger  diameter,  the  thermo-syphon  system  may  be 
used.     The  radiators  using  the  small  pipes  have  a  greater  capacity  for 
their  size  because  they  have  more  exposed  area  for  cooling  in  comparison 
with  the  amount  of  water  they  carry.     The  small  tubes  have  the  dis- 


118  THE  GASOLINE  AUTOMOBILE 

advantage  of  increased  resistance.     This  is  why  it  is  necessary  to  use  a 

pump. 

The  air  for  cooling  purposes  is  usually  drawn  through  the  radiator 
by  a  fan  placed  directly  back  of  it.  This  fan  may  be  driven  with  a  bevel 
or  spur  gear,  with  a  silent  chain,  or  with  a  wire  or  leather  belt.  In  some 
cases,  however,  the  engines  are  air-cooled,  the  cylinders  being  cast  with  a 
large 'number  of  fins  or  rings  on  the  outer  surfaces  to  increase  the  cooling 
effect  of  the  air.  In  this  case  there  is  no  water  jacket. 

The  cooling  system  of  the  Overland  is  the  thermo-syphon  system, 
which  eliminates  the  circulation  pump  and  its  gears,  glands,  stuffing  boxes, 


FIG.  126. — Overland    thermo-syphon    cooling    system. 

etc.  The  thermo-syphon  system  is  automatic,  as  the  speed  with  which 
the  cooling  water  circulates  is  increased  or  decreased  with  every  increase 
or  decrease  in  jacket  temperature.  The  action  of  the  system  is,  briefly,  as 
follows:  The  water  enters  the  cylinder  jackets  A,  Fig.  126.  Upon 
becoming  heated  by  the  explosions  within  the  cylinders,  the  water  ex- 
pands and,  being  lighter,  rises  to  the  top.  It  then  enters  the  pipe  B  and 
passes  into  the  radiator  at  C,  where  it  is  brought  into  contact  with  a  large 
cooling  surface,  D,  in  the  shape  of  the  cellular  radiator.  On  being  cooled, 
and  thereby  contracting  and  becoming  heavier,  the  water  sinks  again  to 
the  bottom  of  the  cooling  system,  to  enter  the  cylinders  once  more  and  to 
repeat  its  circulation.  The  cooling  action  is  further  increased  by  a  belt- 
driven  fan  which  draws  air  through  the  radiator  spaces. 


LUBRICATION  AND  COOLING 


119 


Figure  127  shows  the  cooling  system  on  the  Ford.  This  is  also  a 
thermo-syphon  system,  the  principle  of  operation  being  the  same  as  on 
the  Overland.  The  arrows  indicate  the  path  of  the  cooling  water. 

The  cooling  system  used  on  the  Studebaker  Four  is  the  pump  system 
shown  in  Fig.  128.  The  water  system,  which  contains  10  qt.  of  water, 
consists  of  a  radiator,  hose  connections,  water  line,  pump,  and  water 
jackets  which  are  incorporated  with  the  cylinders.  The  radiator  D 
being  filled  with  water  and  the  motor  running,  the  centrifugal  pump  C 
forces  the  water  to  circulate  as  follows:  From  the  pump  it  is  driven 


FIG.  127. — Ford  cooling  system. 


through  the  lower  water  line  into  the  cylinder  water  jacket,  directly  at 
the  valve  seats,  where  perfect  cooling  is  most  needed.  Here  it  absorbs 
the  heat  and  goes  on  to  the  upper  water  line  and  thence  to  the  radiator. 
In  the  radiator  D  the  water  percolates  slowly  down  through  many  fine 
tubes  F  and  is  cooled  by  the  air  rushing  between  the  fins  surrounding  the 
tubes  and  thence  returns  to  the  pump.  A  fan  G  on  the  front  of  the 
motor,  belted  to  the  crank  shaft,  draws  the  air  through  the  radiator  and 
facilitates  the  cooling  operation.  Figure  128  also  shows  a  standard 
design  of  tubular  radiator.  The  pump,  which  is  of  the  centrifugal  type, 
requires  no  attention  other  than  to  see  that  it  does  not  become  choked 
by  using  dirty  water.  There  is  a  packing  nut  on  the  shaft  which  should 
be  repacked  if  the  pump  should  ever  leak  around  the  shaft  entrance. 


12o  THE  GASOLINE  AUTOMOBILE 

This  can  very  easily  be  done  by  turning  off  the  packing  nut,  removing  the 
old  packing  and  rewinding  the  shaft  with  a  few  inches  of  well  graphited 
packing  and  tightening  up  the  packing  nut.  The  packing  should  be 
wound  on  in  the  same  direction  as  the  nut  is  turned  to  tighten  it. 

The  cooling  system  on  the  Cadillac  Eight  is  of  the  forced  circulation 
type.  The  radiator  is  of  the  tubular  and  plate  type,  with  rotating  fan 
mounted  on  the  forward  end  of  the  generator  driving  shaft,  the  latter 


DRAIN  COCK.    A- 


FIG.  128. — Studebaker  cooling  system. 

being  driven  by  silent  chain  from  the  cam  shaft.  Each  set  of  cylinders  is 
cooled  separately.  Due  to  the  angle  of  jackets,  the  water  does  not  lodge 
in  the  pockets.  The  natural  tendency  is  for  the  water  to  flow  upward 
and  to  rise  to  the  hottest  points. 

There  are  two  centrifugal  water  pumps,  one  on  each  side  of  the 
forward  end  of  the  engine.  These  are  driven  by  a  transverse  shaft  which 
is  driven  by  spiral  gears  from  the  crank  shaft.  Within  each  pump  hous- 
ing is  a  thermostat  shown  in  Fig.  129,  which  controls  a  valve  that  is 
between  the  radiator  and  the  pump. 

When  the  temperature  of  the  cooling  water  drops  below  a  pre- 
determined temperature,  the  thermostats  contract,  thereby  closing  the 


LUBRICATION  AND  COOLING 


121 


valves.  The  water  is  then  circulated  only  through  the  cylinder  blocks 
and  the  carburetor  jacket.  It  returns  to  the  pumps  through  the  water 
jacket  on  the  intake  manifold  and  carburetor.  When  the  thermostats 
are  closed,  none  of  the  water  circulates  through  the  radiator  the  evapora- 
tion of  the  gasoline  in  the  carburetor  and  manifold  providing  sufficient 
cooling  action.  As  the  temperature  of  the  water  rises,  the  thermostats 
expand,  thereby  gradually  opening  the  valves,  permitting  the  water  to 
circulate  through  the  radiator. 


FKOM  T2ADUTOI2. 


PEOMCAEBUJ5JCTIB 
JACKET     ' 


FIG.  129. — Cadillac  thermostatic  control  of  cooling  water. 

The  advantage  in  this  device  is  that,  in  starting  with  a  cold  en- 
gine, the  engine  is  brought  to  a  point  of  highest  efficiency,  in  so  far  as 
heating  is  concerned,  much  more  quickly  than  if  it  were  necessary  to 
heat  the  entire  volume  of  water  before  reaching  that  efficiency.  With 
the  usual  water  circulating  system,  the  highest  efficiency  of  the  engine 
is  not  reached  in  extreme  cold  weather.  An  engine  uses  its  gasoline 
most  economically  when  it  is  running  rather  warm,  and  with  a  radiator 
which  is  adequate  to  prevent  overheating  in  hot  weather,  the  cooling 
is  too  great  for  best  economy  in  extreme  cold  weather. 

The  Cadillac  thermostat  is  simply  a  small  corrugated  copper  tube 
containing  a  liquid  which  expands  or  contracts  in  accordance  with  the 
temperature,  thus  slightly  lengthening  or  contracting  the  tube,  its  total 
movement  being  34  in.  This  thermostat  is  in  connection  with  a  valve 
so  that,  when  it  expands,  it  raises  the  valve  from  its  seat,  this  valve  con- 
trolling the  flow  of  water  to  the  radiator  from  the  pump.  A  by-pass 


122 


THE  GASOLINE  AUTOMOBILE 


connects  with  the  water  jacket  of  the  carburetor,  and  when  the  engine 
is  started,  the  water  is  naturally  cold.  Therefore  the  thermostat  is 
contracted  and  its  valve  is  seated.  Thus  the  radiator  water  is  shut  off, 
the  circulation  being  simply  through  the  water  jackets  of  the  cylinders, 
through  the  by-pass  to  the  carburetor  jacket  and  thence  back  to  the 
cylinders.  There  is  thus  only  a  small  part  of  the  water  circulating,  and 
when  this  heats  up,  the  thermostat  begins  to  expand  and  lifts  its  valve 
from  its  seat,  letting  the  radiator  supply  flow  into  the  system.  This 
action  continues  back  and  forth  so  that  the  water  temperature  is  nearly 
constant. 

88.  Air  Cooling. — The  Franklin  engine,  shown  in  Fig.  130,  shows  a 
good  design  of  an  air  cooling  system.     The  direct  air  cooling  of  the  engine 


FIG.  130. — Franklin   air   cooling   system. 


is  accomplished  as  follows:  The  individual  cylinders  are  provided  with 
vertical  fins  projecting  from  their  periphery.  The  fins  on  each  cylinder 
are  surrounded  by  sheet  metal  jackets  which  form  passages  for  the  air. 
The  flywheel  is  provided  with  a  number  of  curved  blades  so  that  it  has  a 
blower  effect  whenever  the  engine  is  running.  This  forms  a  partial 
vacuum  and  sucks  air  into  the  space  underneath  the  hood  through  the 
grille  in  front.  This  air  passes  in  uniform  quantities  down  through  the 
individual  jackets  on  each  cylinder  into  the  compartment  below  the 
engine  deck  and  hence  out  through  the  fan  blades.  The  fan  is  incor- 
porated in  the  flywheel  and  driven  directly  by  the  engine;  so  a  steady 
stream  of  fresh  air  is  being  continually  drawn  down  over  the  cylinders 
as  long  as  the  engine  is  running. 


LUBRICATION  AND  COOLING  123 

89.  Cooling  Solutions  for  Winter  Use. — In  climates  where  the  tem- 
perature does  not  go  below  a  dangerous  freezing  point,  the  cooling 
medium  used  is  water;  but  in  cold  regions,  where  cars  are  run  a  good 
deal  in  the  winter,  it  is  necessary  to  get  spme  kind  of  anti-freezing 
solution.  The  ideal  requirements  for  an  anti-freezing  compound  are 
as  follows: 

1.  It  should  have  no  harmful  effect  on  any  part  of  the  circuit  with 
which  it  comes  into  contact. 

2.  It  should  be  easily  dissolved  or  combined  with  water. 

3.  It  should  be  reasonably  cheap. 

4.  It  should  not  waste  away  by  evaporation,  that  is,  its  boiling  point 
should  be  as  high  as  that  of  water. 

5.  It  should  not  deposit  any  foreign  matter  in  the  jackets  or  pipes. 
The  principal  materials  used  are:  (1)  oil;  (2)  glycerine;  (3)  calcium 

chloride;  (4)  alcohol;  (5)  mixture  of  alcohol  and  glycerine;  (6)  kerosene 
oil. 

Oil  has  the  advantage  of  having  a  very  high  boiling  point  so  that 
it  will  not  waste  away,  but  it  has  the  disadvantage  that  it  does  not 
make  a  good  mixture  with  water,  and  will  not  absorb  heat  as  rapidly  as 
water.  It  also  has  a  lower  heat  coefficient,  that  is,  it  takes  less  heat  to 
raise  the  temperature  of  a  certain  amount  of  oil  one  degree,  than  it  does 
the  same  amount  of  water.  Oil  cannot  be  used  where  there  is  any  rubber 
in  the  circuit.  It  will  attack  rubber  hose  and  gaskets  very  quickly  and 
they  will  deteriorate  rapidly. 

The  disadvantages  of  using  glycerine  are  similar  to  those  of  the 
oil,  chief  of  which  is  sure  destruction  to  the  rubber  connection.  It  also  is 
liable  to  contain  free  acids,  and  it  is  quite  expensive. 

Calcium  chloride  makes  a  very  good  solution  with  water,  the  freezing 
point  depending  upon  the  proportions  used.  The  general  solution  is  to 
use  5  Ib.  of  the  salt  to  1  gal.  of  water.  This  solution  will  stand  39°  below 
zero  before  freezing.  It  has  the  disadvantage  of  being  very  apt  to  cause 
electrolytic  action  where  two  metals  are  joined  together.  It  is  derived 
from  hydrochloric  acid,  and  is  liable  to  contain  free  acids,  which  attack 
the  metal  very  rapidly.  Calcium  chloride  has  the  same  appearance  as 
chloride  of  lime,  but  has  a  somewhat  different  chemical  composition. 
Pure  calcium  chloride  is  the  only  thing  that  can  be  used.  The  com- 
mercial chloride  of  lime  sets  up  electrolytic  action.  The  solution  may 
be  tested  for  acid  by  dipping  a  piece  of  blue  litmus  paper  in  it.  If  there 
is  any  acid  present,  the  paper  turns  red.  As  the  water  is  evaporated  in 
the  radiator  there  will  be  a  crust  formed  on  the  inside  of  the  jacket,  and 
also  in  the  pipes,  which  has  a  tendency  to  clog  up  and  prevent  circulation. 
The  rate  at  which  these  deposits  occur  depends  on  the  strength  of  the 
solution. 


124  THE  GASOLINE  AUTOMOBILE 

Denatured  alcohol  seems  to  be  about  the  best  substance  to  use  as  a 
non-freezing  solution,  as  it  has  no  destructive  action  whatever  on  either 
metal  or  rubber,  makes  no  deposits  and  never  causes  electrolytic  action. 
A  solution  of  50  per  cent  water  and  50  per  cent  alcohol  will  stand  about 
32°  below  zero.  The  only  disadvantage  that  it  has  is  that  it  evaporates 
more  readily  than  the  water,  so  that  when  adding  new  solution,  more 
alcohol  than  water  must  be  added  in  order  to  keep  the  solution  of  the 
same  strength.  The  combination  of  alcohol,  glycerine  and  water  seems 
to  give  very  good  results.  In  this  combination,  equal  parts  of  alcohol 
and  glycerine  are  used.  The  alcohol  has  a  tendency  to  overcome  the 
destructive  action  of  the  glycerine  or  the  rubber  connections,  and  the 
glycerine  keeps  the  alcohol  from  evaporating  too  rapidly.  The  freezing 
point  depends  on  the  strength  of  the  solution.  A  solution  of  60  per  cent 
water,  and  20  per  cent  each  of  alcohol  and  glycerine  freezes  at  24°  below 
zero.  The  proportions  must  be  governed  by  the  locality  in  which  they 
are  used. 

There  are  also  numerous  anti-freezing  compounds  on  the  market. 
These  are  mostly  put  up  from  some  of  the  materials  mentioned  here. 

In  the  following  tables  are  results  showing  the  temperature  at  which 
some  of  the  well  known  anti-freezing  solutions  will  freeze,  in  various  pro- 
portions of  mixture  with  water  and  with  one  another.  These  are  neces- 
sary, as  different  localities  and  different  altitudes  require  different  solu- 
tions and  every  person  should  be  able  to  select  his  solution  in  the  right 
proportion  to  avoid  having  any  trouble  in  the  coldest  possible  weather 
likely  to  be  experienced  in  his  home  location. 

FREEZING  POINTS  OP  CALCIUM  CHLORIDE  SOLUTIONS 

Per  cent  by  volume  of  Specific  gravity  of  Frppzini?  noint 

calcium  chloride  solution 


10 

1.085 

22°F. 

15 

1.131 

13°F. 

20 

1.119 

0°F. 

22 

1.200 

-9°F. 

24 

1.219 

-  18°F. 

26 

1.242 

-  28°F. 

28 

1.268 

-  42  °F. 

The 

specific    gravity    is 

given    to   be    used 

as    a    check    on 

proportions. 

FREEZING  POINTS  OP  DENATURED  ALCOHOL  MIXED  WITH  WATER 

Per  cent  by  volume  of 
alcohol 

Specific  gravity  of 
solution 

Freezing  point 

10 

0.988 

24°F. 

20 

0.975 

14°F. 

30 

0.964 

—  1°F 

40 

0.954 

-  20°F. 

50 

0.933 

-  32  °F. 

60 

0.913 

-  45°F. 

70 

0.897 

-  57°F, 

the 


LUBRICATION  AND  COOLING  125 

If  wood  alcohol  be  used  instead  of  denatured  alcohol,  slightly  lower 
temperatures  can  be  reached  with  the  same  proportions  of  alcohol  and 
water. 

FREEZING  POINTS  OP  ALCOHOL  AND  GLYCERINE  MIXED  WITH  WATER 

Alcohol  and  glycerine                            Water  Freezing  point 

15  per  cent  85  per  cent  20°F. 

25  per  cent  75  per  cent  8°F. 

30  per  cent  70  per  cent  —    5°F. 

35  per  cent  65  per  cent  —  18°F. 

40  per  cent  60  per  cent  —  24°F. 

45  per  cent  55  per  cent  —  30°F. 

50  per  cent  50  per  cent  -  33°F. 


CHAPTER  VI 
BATTERIES  AND  BATTERY  IGNITION 

All  automobile  engines  in  use  at  the  present  time  have  some  form 
of  electric  ignition,  in  which  a  current  of  electricity  is  made  to  produce  a 
spark  inside  of  the  cylinder.  All  ignition  systems  are  made  up  of  two 
essential  parts:  (1)  the  source  of  electric  current  supply;  and  (2)  the 
apparatus  for  utilizing  this  current  to  produce  a  spark  in  the  cylinder. 

Before  considering  the  features  of  either  of  these  component  parts 
it  is  necessary  that  an  understanding  be  had  of  the  fundamental  electrical 
principles  and  definitions  governing  the  construction  and  operation  of 
electric  ignition  systems. 

90.  Fundamental  Electrical  Definitions. — An  electric  current  flow- 
ing in  a  wire  can  be  compared  to  water  flowing  in  a  pipe  line.     As  the 
water  pressure  is  measured  in  pounds  per  square  inch,  so  the  electrical 
pressure  in  a  wire  is  measured  by  a  unit  called  a  "Volt."     It  is  the  practical 
unit  by  which  electrical  pressures  are  measured. 

The  "Ampere"  is  the  practical  unit  by  which  the  rate  of  current  flow 
in  a  wire  is  measured.  It  corresponds  to  the  number  of  cubic  feet  or 
gallons  which  flow  through  a  water  pipe  per  unit  of  time.  For  a  large 
number  of  amperes,  a  large  wire  is  necessary  and  for  a  smaller  number 
of  amperes,  a  smaller  wire  can  be  used.  We  can  have  a  small  wire  carry- 
ing a  current  of  high  voltage,  and  a  large  wire  carrying  current  of  low 
voltage,  just  the  same  as  a  large  or  small  pipe  can  carry  water  of  either 
high  or  low  pressure.  The  size  of  wire  determines  the  quantity  of  current 
it  can  carry.  A  small  wire  can  carry  a  small  current  but  it  requires  a 
large  wire  to  carry  a  large  current. 

The  "Ohm"  is  the  unit  by  which  the  resistance  to  the  flow  of  electric 
current  through  a  wire  is  measured.  It  corresponds  to  the  friction  op- 
posing the  flow  of  water  through  a  pipe. 

The  Ampere-hour  is  the  measure  of  quantity  of  current.  One 
ampere-hour  is  the  amount  of  current  which  would  flow  at  the  rate  of 
1  amp.  in  1  hour.  It  is  by  this  unit  that  the  capacity  of  storage  batteries 
is  measured.  A  60  ampere-hour  battery  will  give  current  at  the  rate  of 
60  amp.  for  1  hour,  or  at  the  rate  of  30  amp.  for  2  hours,  or  at  the  rate  of 
1  amp.  for  60  hours,  etc. 

91.  Direct  and  Alternating  Current. — Electric  current  can  be  of  two 
kinds :  direct  or  alternating.     Direct  current  always  flows  in  one  direction 
in  the  wire,  and  is  the  kind  of  current  which  is  given  out  by  every  type 

127 


128 


THE  GASOLINE  AUTOMOBILE 


of  battery.  Alternating  current,  however,  first  flows  in  one  direction 
and  then  in  the  other,  the  reversals  taking  place  many  times  per  second. 
It  is  the  kind  of  current  given  out  by  most  of  the  modern  magnetos. 

92.  Dry  Batteries. — The  first  necessary  part  of  an  electric  ignition 
system  is  the  source  of  current.     For  this  purpose  we  can  have  either 
batteries,  dynamos,  or  magnetos.     In  this  chapter  only  batteries  and 
battery  ignition  systems  will  be  discussed.     Magnetos  will  be  treated  in 
the  chapter  on  Magnetos. 

The  dry  battery  is  a  common  source  of  battery  current  for  ignition 
purposes.  It  is  comparatively  cheap,  exceptionally  reliable,  and  can 
be  easily  replaced  when  worn  out.  Due  to  im- 
provements in  the  battery  ignition  systems  its 
use  for  motor  car  ignition  is  growing,  after  hav- 
ing given  way  for  a  time  almost  entirely  to 
magneto  ignition.  Figure  131  is  a  section  of  a 
commercial  dry  cell.  It  consists  of  a  cylindrical 
zinc  shell  around  the  inside  of  which  has  been 
placed  a  piece  of  absorbent  paper  saturated  with 
a  paste  made  of  zinc  oxide,  zinc  chloride,  am- 
monium chloride,  plaster  of  Paris,  and  water. 
The  zinc  can  forms  the  negative  terminal  of  the 
battery,  and  the  carbon  element  down  through 
the  center  of  the  cell  forms  the  positive  terminal. 
The  space  between  the  absorbent  paper  and  the 
carbon  is  filled  with  powdered  carbon  and 

manganese  oxide  which  acts  as  a  depolarizing  agent.  The  voltage  of  a 
dry  cell  is  about  1.5  volts.  The  maximum  possible  amperage  or  current 
of  a  new  cell  ranges  from  20  to  35  amp.,  depending  upon  the  size  of  the 
cell.  The  dry  battery  always  gives  out  direct  current.  The  capacity 
and  life  of  a  dry  cell  depends  on  the  way  it  is  used,  being  greater  when 
it  is  used  intermittently. 

93.  Storage  Batteries. — Although  the  storage  battery  is  to  be  con- 
sidered in  Chap.  VIII  on  Starting  and  Lighting  Systems,  a  brief  descrip- 
tion will  be  given  here  in  order  to  bring  out  clearly  its  functions  in  battery 
ignition  systems.     A  storage  cell,  Fig.  132,  consists  of  two  sets  of  metallic 
plates  placed  in  a  vessel  containing  a  solution  of  sulphuric  acid  and 
water.     In  the  positive  group  the  plates  are  lead  grids,  the  openings  being 
packed  with  lead  peroxide,  characterized  by  its  chocolate  brown  color. 
The  plates  of  the  negative  group  consist  of  finely  divided  sponge  lead. 
These  sets  of  plates  are  placed  in  the  cell  so  that  the  positive  and  negative 
plates  alternate  and  are  separated  by  perforated  sheets  of  hard  rubber 
or  specially  treated  wood.     By  passing  direct  current  into  the  top  of 
one  of  the  plates,  through  the  acid  and  water,  and  out  the  other  plate, 


FIG.  131.— Section  of  dry 
cell.    • 


BATTERIES  AND  BATTERY  IGNITION 


129 


the  plates  are  changed  chemically.  When  the  battery  is  used,  the 
chemical  change  is  reversed  and  the  plates  tend  to  return  to  their  original 
state,  giving  off  current  as  they  do  so.  The  single  storage  cell  of  one 
positive  and  one  negative  set  of  plates  gives,  when  fully  charged,  a  pres- 
sure of  about  2  volts  and  a  current  depending  upon  the  size  and  number 
of  the  plates.  For  ignition  purposes  the  plates  are  connected  so  that  the 
whole  battery  gives  a  voltage  of  from  6  to  8  volts  and  a  capacity  of 
from  60  to  80  ampere-hours. 


Expansion  Chamber  to 
take  care  of  changes  in 
Volume  of  Solution  ' 
rluring  Charge  and  Discharge 


Soft  Rubbct 

Casket 


Polished  Hard 
Rubber  Cover 


Battery  Terminal  covered 
with  a  layer  of  pure  Para 
Rubber  vulcanized  Directly 
to  the  Corrugated  Surface 
.  of  the  Conductor  to  prevent 
creeping  of  acid. 


Plates  and  elements 

ofthe  l    • 
.Villard  Standard 
Faure'  Type 


Treated  Hardwood 
Case  with  Dovetail 

joints.. 


Quadruple     . 
Plate  or  Element  Supports 
of  Hard  Rubber       • 


FIG.  132. — Section  of  Willard  storage  cell. 

94.  Series  and  Parallel  Connections. — The  voltage  of  either  a  dry  or 
storage  cell  is  not  high  enough  for  automobile  engine  ignition  purposes, 
and  methods  of  connecting  several  batteries  must  be  resorted  to  in  order 
to  raise  the  voltage  and  amperage.  A  voltage  of  from  6  to  8  is  necessary 
for  an  ignition  system  using  an  induction  coil.  This  can  be  obtained 
by  the  connection  shown  in  Fig.  133,  in  which  the  carbon  of  one  cell  is 
connected  to  the  zinc  of  the  next.  This  is  known  as  the  "series"  con- 
nection. By  so  connecting  the  cells,  the  resultant  voltage  is  equal  to 
the  combined  voltage  of  all,  or  the  number  of  cells  multiplied  by  the 
voltage  of  one  cell,  which  is  1.5.  The  current  output  is  equal  to  the 
current  of  one  cell  of  the  given  size,  or  about  20  amp.  If  all  the  carbons 
are  connected  and  all  the  zincs  fastened  together,  as  shown  in  Fig.  134, 


130  THE  GASOLINE  AUTOMOBILE 

the  connection  is  known  as  "parallel."  The  resultant  voltage  equals 
the  voltage  of  one  cell  and  the  current  output  equals  the  current  output 
of  one  cell  multiplied  by  the  number  of  cells.  Therefore,  to  increase 
voltage  connect  the  cells  in  series,  and  to  increase  current  output  con- 
nect them  in  parallel. 


5  Dry  cells  in  -series  £  Dry  cef/s  in  parallel 

FIG.  133.  FIG.  134. 

95.  Battery  Connections  for  Ignition  Purposes.  —  Where  the  current 
demand  is  small  or  not  continuous,  a  single  series  of  cells  (usually  five) 
is  used.     This  arrangement  is  suitable  for  single  cylinder  engines,  or  for 
starting  engines  of  two  or  more  cylinders,  where  a  magneto  is  used  after 
the  engine  is  in  operation. 

When  the  amount  of  current  required  is  great,  the  multiple  series 
connection  is  used.  It  is  suitable  for  engines  of  two  or  more  cylinders  and 
continuous  service.  This  arrangement 
consists  of  parallel  groups  of  as  many 
cells  in  a  series  as  may  be  required  for 
the  service.  Figure  135  shows  an  arrange- 
ment with  three  parallel  sets,  each  of  five 
cells  connected  in  series.  This  arrange- 

'•5   cells  in  multiple  series  arrangement  . 

•piQ  13-  ment  provides  for  an  amperage  of  about 

60  at  about  7K  volts. 

Two  series  of  cells  in  multiple  series  connection  will  have  about 
three  times  the  life  of  a  single  series  on  the  same  current,  on  account  of  the 
reduced  rate  of  discharge.  Three  series  connected  in  this  manner  will  give 
about  six  times  the  life  on  the  same  current,  as  would  one  series. 

Another  advantage  of  this  method  of  connection  is  that  a  dead  cell 
will  not  weaken  the  current  from  the  group  enough  to  interfere  with  the 
engine  operation.  For  ordinary  service,  three  groups  of  five  cells  each 
are  frequently  used,  while  for  heavy,  constant  service  five  groups  of  five 
cells  each,  giving  a  voltage  of  about  7.5  and  a  current  of  about  100  amp.  is 
recommended. 

96.  Simple  Battery  Ignition  System.  —  The  jump-spark  or  high-tension 
system  of  ignition  is  so  named  because  a  high  tension  current  is  caused  to 
jump  across  the  gap  between  the  terminals  of  the  spark  plug  in  the  cylin- 
der.    Figure  136  shows  an  elementary  battery  jump-spark  ignition  system 
for  a  one-cylinder  engine.     Four  dry  cells  are  shown  connected  in  series 
giving  a  voltage  of  about  6  and  a  current  of  about  20  amp.     One  terminal 
of  the  battery  set  is  connected  to  the  left  terminal  of  the  induction  or  spark 


BATTERIES  AND  BATTERY  IGNITION 


131 


coil  and  the  other  terminal  to  the  engine  "timer."  The  timer,  or 
commutator,  is  nothing  more  or  less  than  a  mechanically  operated 
"switch,"  placed  between  the  batteries  and  the  right  terminal  of  the  coil. 
The  current  from  the  batteries  goes  to  the  left  terminal  of  the  coil  which  is 
connected  to  a  standard  holding  an  adjustable  contact  serew.  This 
screw  is  in  contact  with  the  vibrator.  Passing  from  the  screw  into  the 
vibrator,  the  current  goes  through  a  comparatively  large  wire  wound 
around  the  central  core.  This  wire  goes  to  the  right  terminal  of  the  coil, 
which  is  connected  back  to  the  timer.  This  circuit  forms  what  is  known 
as  the  "primary"  of  the  system.  When  the  timer  completes  the  circuit, 


SECONDARY       CIRCUIT 


JUMP    SPARK  SYSTEM   OF   IGNITION 
FlG.    136. 

current  flows  through  the  primary  winding.  The  current  flowing  around 
the  iron  core  makes  a  magnet  of  it.  This  fact  causes  the  vibrator  to  be 
pulled  away  from  the  adjusting  screw,  and  this  breaks  the  circuit. 
Consequently,  current  ceases  to  flow,  the  core  loses  its  magnetism,  the 
vibrator  flies  back  to  make  contact  with  the  screw  again,  and  this 
permits  the  primary  current  to  flow,  causing  a  repetition  of  events.  The 
result  is  a  constant  dying  down  and  building  up  of  the  current  in  the 
primary  winding  around  the  core.  This  results  in  a  dying  down  and 
building  up  of  the  magnetism  in  the  core.  It  will  be  noticed  that  there 
is  another  coil  of  finer  wire  wound  around  the  primary  coil  on  the  iron 
core.  This  is  called  the  "secondary"  of  the  coil.  The  ends  of  this 
secondary  winding  are  fastened  to  the  two  secondary  terminals  on  the  top 
of  the  coil.  One  terminal  of  the  coil  is  connected  to  the  spark  plug  in 
the  cylinder  and  the  other  is  connected  onto  the  engine  frame,  or 
"grounded." 

Each  time  the  current  in  the  primary  circuit  is  broken,  there  is  another 
current  of  very  high  voltage  induced  in  the  secondary  winding.  This 
current  is  of  sufficiently  high  electrical  pressure  to  jump  the  spark  plug 
gap  under  the  usual  compression  pressure.  This  voltage  varies  from 


132 


THE  GASOLINE  AUTOMOBILE 


10,000  to  20,000  volts.  The  relation  between  the  voltage  on  the  primary 
circuit  and  that  on  the  secondary  depends  upon  the  relative  number  of 
turns  of  wire  on  the  primary  and  secondary  windings,  upon  the  speed  of 
the  vibrator  and  the  current  in  the  primary  winding. 

In  the  bottom  of  the  coil  is  placed  the  condenser,  consisting  of  alternate 
tinfoil  and  oiled  paper  sheets.  Every  alternate  tinfoil  sheet  is  connected 
to  the  bottom  of  the  standard;  the  ends  of  the  others  are  connected  to  the 
vibrator.  The  current  tends  to  continue  flowing  after  the  circuit  is 
broken  and,  if  it  were  not  for  this  condenser,  there  would  be  a  fat  spark 
across  the  vibrator  points  every  time  the  circuit  was  broken.  The 
condenser  prevents  this  arcing  across  the  vibrator  points,  when  they  break, 
by  absorbing  this  flow  of  current  and  storing  it  until  the  circuit  is  again 
closed.  In  addition,  it  aids  in  the  induction  of  the  high  tension  current 
in  the  secondary  winding  of  the  coil  by  permitting  the  quick  break  of  the 
primary  current. 

The  following  are  the  names  and  functions  of  the  various  parts  of  a 
battery  ignition  system: 

Primary  Circuit. — That  part  of  the  system  carrying  the  battery 
^ ^  current  at  low  voltage— a  few  turns 

Primary  termindJ 

y  ^~  ~~^  w*»«i  Secondary  Circuit.— That  part 

of  the  system  carrying  the  high 
tension  current  to  the  spark  plugs 
— a  great  many  turns  of  very  fine 
wire  on  the  coil. 

Timer. — A  mechanically  oper- 
ated switch  placed  in  the  primary 
circuit.  Its  function  is  to  com- 
plete the  primary  circuit  and  cause 
the  vibrator  to  act,  thus  causing 
a  high  tension  current  to  flow  to 
the  spark  plugs  at  the  proper 
time. 

Vibrator. — A  spring  placed  in 
the  primary  circuit  to  make  and 
break  the  current,  causing  a  high 
tension  current  in  the  secondary. 

Condenser. — An  electrical  ap- 
pliance placed  in  the  primary  cir- 


•Seconcfary  terminal 


FIG.  137. — Three  terminal  vibrating 
induction  coil. 


curt  to  prevent  sparking  at  the  vibrator  points. 

97.  The  Three  Terminal  Coil.— Most  of  the  coils  used  on  automobile 
ignition  systems  have  only  three  terminals  instead  of  four.  One  end 
of  the  primary  winding  is  joined  to  one  end  of  the  secondary  and  the 


BATTERIES  AND  BATTERY  IGNITION 


133 


junction  to  one  of  the  terminal  binding  posts.  The  other  end  of  the 
primary  goes  to  a  primary  binding  post  and  the  other  end  of  the  secondary 
to  the  secondary  binding  post  of  the  coil  as  shown  in  Fig.  137.  An 


FIG.  138. — Pfanstiehl  three  terminal  coil. 


SECONDARY      WIRES  TO     PLUGS 


PRIMARY     WIRES     TO    TIMER 


FIG.  139.  —  Wiring   diagram   for   four-cylinder   engine. 

external  view  of  a  three-terminal  coil  for  a  single-cylinder  engine  is  shown 
in  Fig.  138.  In  Fig.  139  a  four-unit  coil  with  the  wiring  for  a  four-cylinder 
engine  is  shown.  The  three  terminals  are  lettered:  .S,  the  secondary 
terminal  leading  to  the  plug;  P,  the  primary  terminal  to  the  timer;  and  B, 


134  THE  GASOLINE  AUTOMOBILE 

the  terminal  connected  to  the  batteries.  The  secondary  circuit  is  from 
the  secondary  terminal  to  the  plug,  across  the  gap  into  the  engine  frame, 
back  through  the  timer  to  the  coil.  The  primary  circuit  is  from  the 
batteries,  one  side  of  which  is  grounded,  through  the  coil,  to  the  timer, 
where  the  circuit  is  grounded  and  the  current  returns  to  the  batteries 
through  the  metal  of  the  engine. 


FIG.  140. — Pfanstiehl   four-cylinder   coil   set. 


WIRING     DIAGRAM     FOR    4--  CYUIND 
USINO   DRY   CEl-l_S 


FlG.    141. 


Where  a  multiple  cylinder  engine  is  used,  it  is  customary  to  use 
a  coil  for  each  cylinder.  The  coils  are  usually  enclosed  in  an  upright 
box  as  shown  in  Fig.  140,  which  is  a  coil  set  for  a  four-cylinder  engine. 

In  Fig.  141  is  shown  the  arrangement  of  the  ignition  system  for  a 


BATTERIES  AND  BATTERY  IGNITION 


435 


four-cylinder  engine  using  dry  batteries  as  the  source  of  current.  There 
are  two  sets  of  batteries,  one  service  set  and  a  reserve  set.  The  six  cells 
are  connected  in  series,  giving  a  voltage  of  about  9.  The  four  coils  are 
placed  in  one  box,  with  two  small  terminals  at  the  bottom.  Either  of 
these  terminals  is  a  primary  terminal  for  any  one  of  the  four  coils  and  is 
connected  to  the  two  sets  of  batteries.  The  switch  on  the  front  of  the 
box  determines  which  set  of  batteries  will  be  used.  The  other  primary 
terminals  at  the  top  of  the  coils  are  connected  to  the  four  binding  posts 
of  the  timer.  These  terminals  are  also  secondary  terminals.  The  large 
connections  at  the  bottom  of  the  coil  box  are  secondary  wires  leading  to 
the  spark  plugs.  When  the  timer,  which  runs  at  one-half  engine  speed 
or  at  cam  shaft  speed,  grounds  the  primary  circuit  by  the  roller  making 
contact  with  the  insulated  terminal,  a  spark  occurs  in  one  of  the  cylinders, 
depending  upon  the  position  of  the  roller.  Any  of  the  four  coils  may  be 
removed  from  the  box  for  adjustment  or  repair. 


Pull  Rod  Connection 

Case 

Thumb  Nut 

Contact  Point 
Roller  Arm 
Brush 

Engine  Cover 


FIG.  142.— The  Ford  timer. 

98.  Timers. — Figure  142  shows  the  timer  used  on  the  Ford  engine. 
The  inside  or  rotating  part  is  fastened  to  and  rotates  with  the  cam  shaft. 
When  the  roller  comes  into  contact  with  one  of  the  terminals  on  the  hous- 
ing, the  circuit  for  that  coil  is  closed  and  a  current  is  caused  to  flow  in 
the  primary  circuit,   causing  a  spark  in  the  secondary  circuit.     The 
housing  does  not  turn  with  the  cam  shaft,  but  can  be  shifted  back  and 
forth,  either  advancing  or  retarding  the  spark.     The  timer  is  always 
placed  in  the  primary  circuit. 

The  timers  for  six-  and  eight-cylinder  engines  are  similar  to  the  above, 
but  have  six  or  eight  insulated  terminals  on  the  housing  instead  of  four. 

99.  Spark  Plugs. — The  spark  plug  consists  of  two  terminals  fastened 
together,  but  insulated  from  each  other,  and  the  whole  screwed  into  the 
cylinder.     The  center  terminal  is  insulated  from  the  rest  of  the  plug 
and  the  other  terminal.     The  insulation  between  the  center  electrode 
and  the  body  of  a  plug  is  usually  either  of  porcelain  or  of  mica.     The 


136  THE  GASOLINE  AUTOMOBILE 

outside  terminal  is  in  contact  with  the  engine  cylinder  and  is  consequently 
grounded.  The  only  way  the  current  can  get  from  one  terminal  to 
another  is  across  the  air  gap  between  them.  The  gap  between  points 
'of  the  battery  spark  plugs  should  be  about  %2  in., 'or  the  thickness 


FIG.  143. — J.  M.  soot-proof  spark  plug. 


FIG.  144. — Bosch  spark  plug. 


of  a  smooth  dime.     Figure  143  shows  the  exterior  and  interior  arrange- 
ment of  the  J.  M.  soot-proof  plug.     In  Fig.  144  is  shown  the  side  and 
, "— — =— •  bottom   views   of   the   Bosch   plug   with   three 

~~->w          grounded  electrodes. 

100.  Master  Vibrators. — In  order  to  avoid 
the  four  vibrator  adjustments  on  the  four-coil 
systems,  and  the  possibility  of  getting  sparks  of 
different  intensity  in  the  different  cylinders,  a 
master  vibrator  is  sometimes  used.  A  master 
vibrator  is  an  additional  coil  with  only  a  primary 
winding,  one  vibrator,  and  a  condenser.  It  is 
placed  between  the  batteries  or  source  of  cur- 
rent and  the  primary  windings  of  the  coils. 
The  vibrators  of  the  coils  are  then  screwed  down 
tight  or  short-circuited  by  a  copper  wire  as 
shown  in  Fig.  146.  The  master  vibrator  serves 
for  all  four  coils  and,  when  once  adjusted,  the 
sparks  in  all  the  cylinders  will  be  of  the  same 
intensity.  There  is  only  one  vibrator  to  be 

adjusted  and  to  get  out  of  order  instead  of  four.  The  principle  of  the 
master  coil  is  that  the  winding  of  the  coil  and  the  vibrator  are  connected 
successively  in  series  with  the  primary  windings  of  each  individual  coil. 


FIG.  145.— Pfanstiehl 
master  vibrator. 


BATTERIES  AND  BATTERY  IGNITION 


137 


This  produces  the  make  and  break  in  the  primary  winding  of  the  coil. 
Figure  145  illustrates  the  outside  view  of  the  Pfanstiehl  master  vibrator. 
Figure  146  shows  the  application  of  the  K-W  master  vibrator  with  both 
battery  and  magneto  sources  of  current. 


FIG.  146. — Connections  for  K-W  master  vibrator. 

101.  The  High  Tension  Distributor  System. — A  typical  high  tension 
distributor  system  is  shown  in  Fig.  147.  This  system  enables  a  single 
coil  to  be  used  to  serve  a  number  of  cylinders.  The  particular  feature 
of  this  system  is  the  combined  low  tension  timer,  or  interrupter,  and 
the  high  tension  or  secondary  distributor,  acting  with  a  single  non- 


FIG.  147. — High  tension  distributor  system. 

vibrating  coil.  In  this  particular  illustration,  two  sets  of  dry  cells  are 
provided,  one  set  being  in  reserve.  The  distributor  and  timer  are  usually 
mounted  in  a  vertical  position  in  a  single  unit  and  are  driven  at  cam  shaft 
speed  by  a  vertical  shaft.  The  coil,  as  mentioned  before,  is  non-vibrating. 
The  mechanical  contact  maker,  or  interrupter  form  of  timer  located 
under  the  high  tension  distributor,  serves  in  place  of  the  usual  vibrator 
on  the  coil. 


138 


THE  GASOLINE  AUTOMOBILE 


The  primary  current  flows  out  of  the  batteries  into  the  bottom 
primary  terminal  of  the  coil,  out  of  the  center  primary  terminal  and  over 
to  the  primary  binding  post  on  the  timer.  The  revolving  contact  maker 
completes  the  circuit  by  grounding  the  current  through  the  timer  shaft. 
This  contact  maker  or  timer  is  constructed  so  as  to  give  a  very  quick 
break  to  the  primary  circuit  so  that  there  will  be  a  high  pressure  current 
induced  in  the  secondary  winding  of  the  coil.  This  flows  out  of  the 


FIG.  148. — Connecticut  type  E  ignition  system. 

secondary  terminal  of  the  coil  to  the  main  terminal  post  of  the  distributor, 
where  it  is  sent  to  one  of  the  four  spark  plugs,  depending  on  the  position 
of  the  distributor  arm.  The  action  of  a  distributor  is  much  like  that  of 
an  ordinary  timer  used  with  vibrating  coils,  though  its  construction  to 
handle  secondary  high  tension  current  is  necessarily  much  different.  In- 
stead of  producing  a  series  of  sparks  in  the  cylinder,  as  is  done  with  the 
vibrating  coil,  the  mechanical  interrupter  produces  only  one  fat  spark  in 
each  cylinder. 

This  arrangement  is  not  so  complicated  as  the  multiple  coil  system. 
There  is  only  one  adjustment,  that  at  the  contact  maker,  and  this  insures 
sparks  of  the  same  intensity  in  each  of  the  cylinders.  The  drain  on  the 
batteries  is  also  less,  as  only  one  spark  is  produced  in  each  cylinder,  in 
contrast  to  the  series  of  sparks  produced  by  a  vibrating  coil. 


BATTERIES  AND  BATTERY  IGNITION 


139 


102.  The  Connecticut  Automatic  Ignition  System. — This  system 
operates  on  the  high  tension  distributor  principle,  using  but  one  coil  for 
all  cylinders.  It  employs  a  mechanical  interrupter  for  the  primary  cur- 
rent. Although  dry  batteries  can  be  used  in  cases  of  emergency,  the 
system  is  primarily  intended  for  the  use  of  storage  batteries  as  the  source 
of  current.  Its  ideal  use  is  in  conjunction  with  a  generator  supplying 
current  to  a  storage  battery  for  lighting  and  starting.  Figures  148  and 
149  are  wiring  diagrams  showing  the  connections  for  the  Connecticut 


FIG.  149. — Connecticut  type  G  ignition  system. 

types  E  and  G  systems.  The  essential  difference  between  these  systems 
is  in  the  switch  and  coil  connections.  In  type  E  the  coil  is  integral 
with  the  switch  and  is  designed  to  be  placed  under  the  hood,  thus  assist- 
ing in  preserving  a  clean  dash.  Type  G  has  a  separate  switch  and  coil, 
which  permits  its  application  where  the  space  is  limited,  as  for  instance 
when  the  gasoline  tank  is  carried  in  the  cowl  dash.  The  switch  is 
mounted  on  the  dash  and  the  coil  any  place  on  the  engine  near  the  ig- 
niter, thus  bringing  the  condenser  close  to  the  breaker  points  and  elimi- 
nating the  necessity  of  extending  the  high  tension  wires  to  the  dash. 


140 


THE  GASOLINE  A  UTOMOBILE 


The  combined  interrupter  and  high  tension  distributor  is  clearly 
shown  in  Figs.  150,  151,  and  152.  The  interrupter,  Fig.  150,  first  closes 
the  circuit  and  permits  battery  current  to  flow  through  the  primary 
circuit.  When  one  of  the  lobes  on  the  cam  strikes  the  roller,  the  circuit 


FIG.  150. — Connecticut  interrupter. 


FIG.  151. — Connecticut  igniter  with 
distributor  cap  removed. 


FIG.  152.— Connecticut  igniter 
assembled. 


^^^•^^^ 

FIG.  153. — Connecticut  type  E  coil  and 
switch  with  cover  removed  to  show 
terminal  connections. 


is  opened  and  a  high  voltage  is  thus  produced  in  the  secondary  winding  of 
the  coil.  The  high  tension  current  is  distributed  to  the  plugs  by  the 
distributor  of  the  instrument.  The  distributor  and  interrupter  are 


BATTERIES  AND  BATTERY  IGNITION 


141 


mounted  in  a  single  unit  as  shown  in  Fig.  152,  the  whole  device  being 
called  the  igniter. 

The  igniter  is  mounted  on  a  vertical  shaft  running  at  one-half  engine 
speed  and  thus  can  be  mounted  the  same  as  the  ordinary  timer  for 
vibrating  coils.  Figure  153  shows  the  arrangement  of  the  coil  terminals. 
It  will  be  noted  that  a  spark  gap  is  provided  to  protect  the  secondary 
winding  from  the  destructive  action  of  the  high  voltage  in  case  a  plug 
terminal  becomes  disconnected  so  that  the  high  tension  current  can  not 
take  its  regular  path.  The  safety  gap  is  placed  in  a  glass  tube  inaccessible 
to  vapor  or  fumes.  It  is  conveniently  arranged  for  observation  in  cases 
of  missing  cylinders. 

The  spark  advance  and  retard  in  the  Connecticut  system  are  effected 
by  swinging  the  entire  igniter  housing  either  forward  or  back. 

103.  The  Atwater  Kent  System. — The  Atwater  Kent  system  is  also  of 
the  high  tension  distributor  type  and  has  as  an  optional  feature  the 


CONTACT  MAKER 


FIG.  154.  —  Diagram  showing  principle  of  Atwater 
Kent  system. 


FIG".  155. — Exterior  of 
unisparker. 


automatic  spark  advance,  which  automatically  regulates  the  position  of 
the  spark  according  to  the  speed  of  the  engine.     This  system  is  designed 
to  operate  in  a  satisfactory  manner  with  dry  cells  as  the  source  of  current. 
The  Atwater  Kent  system  consists  of  two  main  parts: 

(1)  The  unisparker,  which  is  the  contact  maker  and  the  distributor 
combined  in  one  small  case  mounted  on  the  timer  shaft  of  the  engine. 

(2)  The  coil,  which  consists  of    a    simple  primary  and    secondary 
winding  with  condenser.    The  coil  has   no  vibrators  or  other  moving 
parts,  this  function  being  served  by  the  contact  maker.     The  principle 
of  the  Atwater  Kent  system  is  clearly  shown  in  Fig.  154.     The  battery 
current  is  closed  and  broken  by  the  mechanical  contact  maker.     The 
secondary    current   from  the  coil  goes   to  the  distributor,  where  it  is 


142 


THE  GASOLINE  AUTOMOBILE 


directed  to  the  proper  plug.     The  distributor  and  contact  maker  are 
built  together  and  are  called  the  unisparker. 

The  unisparker,  Type  K-2,  is  illustrated  in  Fig.  155.  It  is  connected 
to  the  ordinary  timer  shaft  of  the  engine,  the  dome-shaped  cover  con- 
taining the  primary  contact  maker  and  the  secondary  distributor  as 
well  as  the  spark  advancer.  By  releasing  the  two  spring  clips,  the 


FIG.  156. — Atwater  Kent  contact  maker. 

rubber  dome  is  lifted  and  the  contact  maker  exposed.  The  contact  maker 
of  the  unisparker  is  shown  in  Fig.  156.  As  will  be  seen  from  investigation, 
only  one  spark  is  produced  per  explosion  stroke,  as  the  circuit  is  made 
and  broken  but  once.  An  important  feature  of  this  contact  maker 
is  that  the  length  of  contact  is  absolutely  independent  of  the  engine  speed, 
and  as  strong  a  spark  is  produced  when  the  engine  is  cranked  by  hand  as 
when  the  latter  runs  at  normal  or  even  at  racing  speed.  The  length  of 


FIG.  157. — Operation  of  contact  maker. 

contact  is  constant  and  no  greater  at  any  speed  than  is  necessary  to 
insure  the  magnetic  field  of  the  coil  being  built  up  to  its  full  strength. 

The  action  of  the  contact  maker  is  shown  in  Fig.  157.  The  hardened 
steel  rotating  shaft  in  the  center,  the  lifter,  the  latch,  and  the  contact 
spring  are  the  principal  moving  parts.  The  contact  is  made  and  broken 
by  the  action  of  the  lifter  spring  in  drawing  the  lifter  back,  after  it  has 


BATTERIES  AND  BATTERY  IGNITION 


143 


become  unhooked  from  the  notched  shaft.  This  spring  action  makes  the 
speed  of  the  break  independent  of  the  speed  of  the  engine.  It  also  makes 
the  time  of  contact  uniform,  and  this  is  adjusted  so  as  to  use  the  least 
possible  current  from  the  batteries. 

Directly  above  the  contact  maker 
is  located  the  high  tension  distributor. 
This  consists  of  a  revolving  hard  rub- 
ber block  driven  by  means  of  a  key 
from  the  end  of  the  operating  shaft 
and  carrying  a  contact  segment  on  its 
circumference.  Two,  four  or  six  con- 
tact pins,  depending  on  the  number  of 
cylinders,  are  secured  into  the  hard 
rubber  cover  plate  of  the  device,  which, 
as  already  stated,  forms  the  body  of 
the  distributor.  Proper  cable  connec- 
tions are  formed  on  the  terminals  of 

the  cover  plate  and,  from  these,  connection  is  made  to  the  individual 
spark  plugs. 

The  coil  used  in  connection  with  the  Atwater  Kent  system  consists  of 
simple  primary  and  secondary  windings  of  generous  proportions,  which, 


FIG.  158. — Atwater  Kent  kick 
switch  coil. 


Motor  stopped  or  running  slowly.  Motor  at  high  speed. 

FIG.  159. — Atwater    Kent    automatic    spark    advance    mechanism. 

together  with  a  condenser,  are  sealed  into  a  container.     There  are  no 
moving  parts  or  adjustments. 

One  of  three  types  of  coils  is  usually  furnished  with  the  Atwater 
Kent  system:  a  simple  plate  switch  coil,  a  kick  switch  coil,  shown  in  Fig. 
158,  or  an  underhood  coil  with  separate  switch.  Both  plate  and  kick 

15 


144 


THE  GASOLINE  AUTOMOBILE 


switches  are  provided  with  a  push  button  for  producing  starting  sparks 
without  cranking. 

Automatic  Spark  Advance.— -Figure  159  shows  the  centrifugal  gov- 
ernor which  advances  the  spark  as  the  speed  increases.  The  rotating 
shaft  is  divided,  and  as  the  governor  weights  expand  they  rotate  the 
upper  part  of  the  shaft  forward  in  its  own  direction  of  rotation,  thus 
making  and  breaking  contact  earlier  than  at  slow  speed. 

In  Fig.  160  the  wiring  diagram  of  the  Atwater  Kent  installation  is 
shown.  Among  the  particular  features  of  this  system  are:  time  of 
closed  primary  circuit  is  independent  of  engine  speed;  speed  of  break  is 
independent  of  engine  speed;  circuit  cannot  be  closed  when  engine  is 
stopped;  battery  consumption  is  reduced  to  a  minimum;  the  spark  is 
uniform  in  all  cylinders  and  is  independent  of  engine  speed. 


FIG.  160. — Atwater  Kent  wiring  diagram. 

104.  The  Westinghouse  Ignition  System. — There  are  several  igni- 
tion systems  made,  particularly  for  cars  equipped  for  electric  starting 
and  lighting,  in  which  the  source  of  current  is  a  storage  battery  kept 
charged  at  all  times  by  the  starting  and  lighting  generator.  In  some, 
the  generator  simply  keeps  the  battery  charged  and  the  ignition  system 
is  entirely  separate  but  draws  its  current  from  the  battery.  In  others, 
the  generator  carries  the  interrupter  and  the  high  tension  distributor  for 
the  purpose  of  timing  and  distributing  the  current. 

The  Westinghouse  system  of  ignition  is  mounted  as  a  unit  with  the 
electric  generator  which  supplies  electric  current  to  the  storage  battery 
for  lighting  or  starting  or  both.  When  the  engine  is  not  running  or  is 
operating  at  very  low  speed,  the  ignition  current  is  supplied  entirely  by 
the  battery.  After  the  engine  reaches  a  certain  speed,  the  current  may 
be  supplied  in  whole  or  in  part  by  the  generator. 

The  ignition  outfit  consists,  in  addition  to  the  generator  and  storage 
battery,  of  an  ignition  switch  and  coil  on  the  dash,  and  an  interrupter 
and  distributor  which  are  made  a  part  of  the  generator.  The  ignition 
coil  transforms  the  voltage  of  the  battery  up  to  the  high  tension  required 
for  the  spark  plugs.  The  interrupter  closes  and  then  opens  the  ignition 
circuit  at  each  half  revolution  of  the  generator  shaft,  and  the  distributor 


BATTERIES  AND  BATTERY  IGNITION 


145 


directs  the  high  tension  current  to  each  of  the  spark  plugs  in  succession. 
Figure  161  shows  the  exterior  of  the  generator  with  the  distributor  and 
interrupter  on  the  right  hand  end. 


FIG.  161. — Westinghouse   ignition   and   lighting  generator. 

The  view  of  the  generator  disassembled,  Fig.  162,  shows  the  principal 
parts.  This  system  has  an  automatic  spark  advance  operated  by 
centrifugal  weights  inside  the  interrupter. 


FIG.   162. — Parts  of  Westinghouse  ignition  and  lighting  generator. 

Figure  163  illustrates  the  interrupter  with  the  centrifugal  weights 
and  springs  in  the  position  they  occupy  when  the  engine  is  at  rest. 
Figure  164  shows  the  position  that  the  weights  occupy  when  the 
engine  is  running  at  high  speed. 

The  operation  of  the  ignition  system,  including  the  interrupter  and 


146  THE  GASOLINE  AUTOMOBILE 

distributor,  ignition  coil  and  switch,  begins  with  the  "making"  of  the 
primary  circuit  of  the  coil  when  the  centrifugal  weights  push  down  the 


FIG.  163. — Westinghouse  generator  with  distributor  and  interrupter  cover  removed. 

fiber   bumper,   forcing   the   interrupter   contacts   to    close.     Then   the 
weight  moves  off  the  fiber  bumper,  allowing  the  contacts  to  suddenly 

separate    or    open.     This    break    of    the 

primary  circuit  induces  a  high  voltage 
in  the  secondary  of  the  ignition  coil. 
This  is  led  to  the  distributor,  which  di- 
rects it  to  the  proper  spark  plug,  caus- 
ing a  spark  at  the  spark  plug  gap.  As 
the  speed  of  the  engine  increases,  the 
weights  are  thrown  out  from  the  center 
and  automatically  advance  the  time  of 
closing  or  opening  the  interrupter  con- 
FIG.  164. — Westinghouse  in-  tacts,  and  hence  advance  the  spark.  At 

the  Same    time>   due  to  their  shaP6>  ^ 
keep  the  contacts  closed  during  a  longer 
period  of  the  revolution  when  running  at  high  speed;  this  makes  the 


BATTERIES  AND  BATTERY  IGNITION 


147 


length  of  time  of  contact  practically  the  same  at  all  speeds  and  prevents 
the  spark  voltage  from  falling  off  at  high  speeds. 

In  generators  not  provided  with  automatic  spark  advance  the  cen- 
trifugal weights  are  omitted  and  a  solid  cam  substituted.  The  interrupter 
contacts  are  changed  so  as  to  make  the  breaking  of  the  contact  occur 
when  the  lever  is  pushed  down  by  the  cam  instead  of  when  being 
returned  by  the  spring. 

105.  The  Delco  System  of  Ignition. — All  the  Delco  systems  are  not 
identical,  there  being  slight  changes  to  adapt  them  to  the  different  cars. 
For  example,  the  ignition  coil  on  some  cars  is  mounted  on  the  dash,  or 
on  top  of  the  starting  motor-generator  instead  of  on  the  side,  as  shown 
in  Fig.  165. 

All  current  for  lights,  horn,  and  ignition  is  supplied  first  to  the  com- 
bination switch,  and  after  passing  through  the  protective  circuit  breaker 


FIG.  165. — Delco  ignition  system. 

on  the  dash  is  distributed  to  these  different  units.  When  the  generator 
is  supplying  the  current,  it  comes  from  the  forward  terminal  on  the  side 
of  the  generator  through  the  wire  A  to  the  switch.  The  storage  battery 
current  is  connected  through  the  wire  B.  If  the  button  B  is  pulled  out, 
the  current  from  the  dry  cells  is  used  for  ignition.  If  button  M  is  pulled, 
the  current  will  be  taken  either  from  the  generator  or  storage  battery, 
depending  on  whether  or  not  the  generator  is  in  operation.  Thus,  either 
the  M  or  B  button  may  be  used  for  starting. 

The  excess  current  from  the  generator  flows  through  the  wire  B  to 
the  storage  battery.  An  ammeter  inserted  in  the  line  A  would  indicate 
the  amount  of  current  coming  from  the  storage  battery  to  the  generator 
when  the  engine  is  not  running,  or  it  would  indicate  the  current  being 
generated  when  the  engine  is  running. 

Distributor  and  Timer. — The  distributor  and  timer  is  carried  on  the 


148  THE  GASOLINE  A  UTOMOBILE 

front  of  the  motor-generator,  and  is  driven  through  a  set  of  spiral  gears 
attached  to  the  armature  shaft.  The  distributor  consists  of  a  cap  or 
head  of  insulating  material,  carrying  one  high  tension  contact  in  the 
center,  with  similar  contacts  spaced  equidistant  about  the  center,  and 
a  rotor  which  maintains  constant  communication  with  the  central 
contact.  The  rotor  carries  a  contact  button  which  serves  to  close 
the  secondary  circuit  to  the  spark  plug  in  the  proper  cylinder. 

Beneath  the  distributor  head  and  its  rotor  is  the  timer,  a  diagram 
of  which  is  shown  in  Fig.  166.  This  is  provided  with  a  screw  A  in  the 
center  of  the  shaft,  the  loosening  of  which  allows  the  cam  to  be  turned  in 
either  direction  to  secure  the  proper  timing,  turning  in  a  clockwise  direc- 
tion to  advance  and  counter-clockwise  to  retard.  The  spark  occurs  at 
the  instant  the  timer  contacts  are  opened. 


FIG.  166.— The  Delco  timer. 

A  weight  on  the  timer  shaft  acts  as  a  centrifugal  governor  to  operate 
the  automatic  spark  control.  In  addition  to  the  automatic  spark  con- 
trol a  manual  control  is  provided,  which  is  operated  by  a  lever  on  the 
steering  column,  and  is  connected  to  the  lever  at  the  bottom  of  the  motor 
generator.  The  manual  spark  control  is  for  the  purpose  of  securing  the 
proper  ignition  control  for  variable  conditions  such  as  starting,  differences 
in  gasoline,  and  weather  conditions.  The  automatic  control  is  for  the 
purpose  of  securing  the  proper  ignition  control  necessary  for  the  varia- 
tions due  to  speed  alone. 

The  Coil. — The  ignition  coil  is  the  dark  vertical  cylinder  shown  on  the 
front  side  of  the  motor  generator  in  Fig.  165.  It  serves  to  transform 
the  low  voltage  current  in  the  primary  circuit  to  a  current  of  high  voltage 
in  the  secondary  circuit.  The  coil  consists  of  a  primary  winding  of 
coarse  wire  wound  around  an  iron  core  in  comparatively  few  turns,  and 
of  a  secondary  winding  of  many  turns  of  fine  wire,  also  the  necessary 
insulation  and  terminals  for  wiring  connections. 


BATTERIES  AND  BATTERY  IGNITION 


149 


106.  The  Remy-Studebaker  Ignition  System. — This  system,  shown 
in  Fig.  167,  is  built  by  the  Remy  Electric  Co.  and  is  used  on  the  Stude- 
baker  car.  It  is  of  the  high  tension  distributor  type  with  the  primary 
current  furnished  by  the  storage  battery.  Dry  batteries  are  supplied  for 
emergency  purposes.  The  storage  battery  is  kept  charged  by  the  starting 
generator.  The  distributor  and  breaker  box  form  an  individual  unit, 
as  shown  in  Figs.  168  and  169.  Figure  169  shows  clearly  the  operation 
of  a  distributor,  the  current  entering  at  the  center  and  being  directed  by 


TO    O 
TO    P 


FIG.  167. — Wiring  diagram  of  Remy-Studebaker  ignition  system. 

the  revolving  arm  to  the  different  contact  plates  on  the  inside  of  the  cover. 
These  connect  to  the  different  plugs. 

The  transformer  coil  is  of  the  non-vibrating  type  furnishing  a  single 
spark,  the  interruption  of  the  primary  circuit  taking  place  in  the  breaker 
box.  Inside  the  breaker  box  is  the  primary  interrupter  or  circuit  breaker. 
By  the  action  of  the  cam  D  the  two  points  A  and  B  close  and  open  twice 
in  each  revolution  of  the  shaft.  These  points  are  in  the  circuit  of  the 
current  flowing  from  the  battery  to  the  primary  coil  winding.  The 
interruption  of  this  current  induces  a  high  tension  current  in  the  secondary 
winding  of  the  coil.  The  interrupter  makes  two  sparks  to  one  revolution 
of  its  shaft  and  therefore  must  run  at  twice  the  speed  of  the  distributor 


150 


THE  GASOLINE  AUTOMOBILE 


FIG.  168. — Face  and  side  views  of  Remy-Studebaker  distributor  and  breaker  box. 


BREAKER  BOX 
COVER  0 


BREAKER 
BOX  N 
D 


FIG.  169. — Remy-Studebaker  igniter  disassembled. 


BATTERIES  AND  BATTERY  IGNITION 


151 


for  a  four-cylinder  engine.     For  six  cylinders  it  would  make  three  revolu- 
tions to  one  of  the  distributor. 

107.  Spark  Advance  and  Retard.— It  is  very  essential  in  a  variable 
speed  gasoline  engine  that  the  time  at  which  the  spark  occurs  in  the  cylinder 
be  changed  according  to  the  engine  speed,  as  it  takes  a  certain  length  of 
time  to  produce  an  explosion,  regardless  of  the  engine  speed.     When  the 
engine  speed  is  high,  the  spark  must  occur  before  the  piston  reaches  dead 
center  in  order  to  have  the  full  force  of  the  explosion  when  the  piston  has 
just  passed  the  center  position.     When  the  engine  speed  is  slower,  the 
spark  can  occur  later  and  yet  have  the  force  of  the  explosion  exerted 
just  after  dead  center.     It  is  necessary  when  starting  that  the  spark  occur 
not  before  dead  center. 

These  various  considerations  de- 
mand that  the  position  of  the  spark 
be  made  variable.  This  is  usually 
done  by  shifting  the  timer,  or  inter- 
rupter housing,  causing  the  break  of 
the  primary  current  (and  conse- 
quently the  spark  in  the  cylinder) 
to  occur  earlier  or  later.  The  posi- 
tion of  the  spark  is  in  most  cases 
governed  from  the  steering  column. 
In  starting  the  engine,  the  spark 
should  not  occur  until  after  the  pis- 
ton has  started  on  its  down  stroke. 
It  should  then  be  advanced  as  the 
engine  increases  its  speed.  If  the 
spark  is  too  far  advanced  there  will 
be  a  decided  knock  in  the  cylinders. 

108.  Automatic  Spark  Advance. — In  several  modern  ignition  systems, 
means  are  provided  by  which  the  position  of  the  spark  is  automatically 
advanced  and  retarded.     This  relieves  the  driver  from  the  responsibility 
and  uncertainty  of  correctly  gauging  the  position  at  which  to  set  the  spark 
lever.     Figure  170  shows  the  Delco  spark  advance  mechanism  used  on 
the  Cadillac.     As  is  seen,  it  consists  of  a  ring  governor  which  determines 
just  when  the  timer  contact  breaks.     As  the  engine  speeds  up,  the  ring 
swings  nearer  to  a  horizontal  position  and  this  shifts  the  interrupter  cam 
so  that  the  circuit  is  broken  earlier.     A  spring  pulls  them  back  when  the 
engine  slows  down.     The  mechanism  of  the  Atwater  Kent  automatic 
spark  advance  was  shown  in  Fig.  159  and  that  of  the  Westinghouse  system 
in  Figs.  163  and  164. 


FIG.  170.- — Delco  automatic  spark 
advance  mechanism  as  used  on  Cadillac 
cars. 


CHAPTER  VII 
MAGNETOS  AND  MAGNETO  IGNITION 

109.  Principles  of  Magnetism. — The  principle  upon  which  a  magneto 
is  constructed  involves  an  understanding  of  some  elementary  magnetic 
and  electrical  principles  in  addition  to  those  discussed  in  the  preceding 
chapter. 

Magnets. — It  is  a  well  known  fact  that  either  in  a  bar  magnet  or  in  a 
magnet  bent  in  the  shape  of  a  horseshoe,  as  in  Fig.  171  the  "magnetism," 
that  invisible  force  which  attracts  and  repels  iron  or  steel,  is  concentrated 
near  the  ends,  as  indicated  by  the  bunches  of  iron  filings  at  the  ends  of 
these  magnets.  One  end  of  the  magnet  is  called  the  "north"  or  N-pole, 


FIG.  171. 

and  the  other  the  "south"  or  S-pole.  The  difference  between  the  two 
poles  can  be  seen  by  taking  two  horseshoe  magnets  and  placing  their  like 
poles  and  again  their  unlike  poles  together.  It  will  be  found  that  the 
"like"  poles  repel  each  other  and  the  "unlike"  poles  attract  each  other, 
This  is  the  fundamental  law  of  magnetism. 

Lines  of  Force. — If  a  horseshoe  magnet  be  placed  on  its  side,  as  shown 
in  Fig.  172,  a  piece  of  paper  put  over  it,  and  iron  filings  be  sprinkled  over 
the  paper,  we  shall  find  that  the  filings  arrange  themselves  in  well- 
defined  lines,  their  direction  being  as  indicated.  This  arrangement 
shows  us  that  there  is  a  magnetic  force  acting  between  the  two  poles  of 

153 

17 


154  THE  GASOLINE  AUTOMOBILE 

the  magnet.  The  direction  is  shown  and,  if  the  investigation  be  con- 
tinued, it  will  be  discovered  that  this  invisible  force  acts  from  north  pole 
to  south  pole.  These  invisible  lines  are  known  as  magnetic  "lines  of 
force." 

Permanent    and    Electro+magnets. — Horseshoe    magnets    are    either 
"permanent"    or    "electro"    magnets.     A    permanent    magnet    is    one 


FIG.  172. 

made  of  highly  tempered  steel  which  has  been  magnetized  and  usually 
retains  its  magnetism  indefinitely.  An  electro-magnet,  Fig.  173,  is  made 
of  wrought  iron  or  soft  steel,  and  carries  a  coil  of  wire  through  which  a 
current  of  electricity  is  passed  when  the  iron  or  steel  is  to  become  mag- 
netized. As  soon  as  the  current  in  the  wire  is  cut  off,  the  magnet  loses 
its  magnetism.  The  name  "electro-magnet"  signifies  that  the  mag- 


FIG.  173. — Electro-magnet.        FIG.  174. — Simple  magnet.     Compound  magnet. 


netism  is  the  effect  of  the  electric  current.  In  the  mechanical  generation 
of  current  we  shall  see  that  the  magnetism  in  the  horseshoe  magnet  is 
made  use  of.  If  a  permanent  magnet  is  used  for  creating  the  magnetic 
field,  the  machine  is  called  a  "magneto"  and  if  electro-magnets  are 
used,  the  machine  is  called  an  electric  generator. 


MAGNETOS  AND  MAGNETO  IGNITION 


155 


•Magnets 


Simple  and  Compound  Magnets. — In  some  types  of  magnetos,  com- 
pound permanent  magnets  are  used.  A  compound  magnet  is  one  built 
up  of  several  simple  magnets,  as  shown  in  Fig.  174.  It  has  been  found 
that  a  compound  magnet  is  much  stronger  than  a  simple  magnet  of  the 
same  size. 

110.  Mechanical  Generation  of  Current. — It  is  found  that  if  a  wire 
be  moved  across  the  magnetic  field  be- 
tween the  poles  of  a  magnet  so  as  to 
cut  the  "lines  of  force"  there  will  be 
an  electric  current  generated  in  the 
wire.  If  the  wire  should  now  be  moved 
across  the  lines  of  force  in  the  opposite 
direction,  the  current  will  also  flow  in 
the  opposite  direction  in  the  wire.  The 
reason  for  this  is  not  clearly  explained, 
but  it  is  a  well  known  fact  that  cutting 
magnetic  lines  of  force  by  moving  a 
wire  across  them  will  generate  current 
in  the  wire. 


Pole  pieces 


Rotating  armature 

FIG.  175. 


This  fact  is  made  use  of  in  the  mag- 
neto, an  elementary  type  of  which  is 
shown  in  Fig.  175.  The  wire  has  been  formed  in  the  shape  of  a  rect- 
angle and  arranged  to  rotate  between  the  pole  pieces  of  the  magnet. 
If  the  ends  of  the  wire  are  connected  by  a  measuring  instrument,  a  current 
of  electricity  will  be  found  to  flow  out  of  one  end  of  the  wire  and  into 
the  other  end  as  the  wire  is  revolved.  This  current  will  be  an  alternating 
current;  that  is,  the  current  changes  in  direction  each  time  the  rectangle 


FIG.  176. 

turns  over.  When  the  wire  is  cutting  the  "lines  of  force"  at  right  angles 
the  voltage  is  the  maximum,  and  it  is  at  this  period  of  rotation  that  the 
current  is  best  for  ignition  purposes.  This  condition  occurs  twice  during 
a  complete  revolution  of  the  loop  of  wire. 

In  an  actual  magneto,  instead  of  having  only  one  turn  of  wire,  a 


156  THE  GASOLINE  AUTOMOBILE 

great  many  turns  of  wire  are  wound  in  the  shape  of  a  coil  around  a  piece 
of  laminated  iron,  called  the  armature  core.  This  coil  is  caused  to  rotate 
between  the  magnetic  poles,  generating  a  current  in  it.  Figure  176 
illustrates  the  change  and  cutting  of  the  magnetic  lines  of  force  during 
one  complete  revolution  of  the  armature.  By  using  the  laminated 
iron  armature  core,  the  flow  of  the  magnetism  between  the  poles  of  the 
magnet  is  increased,  thus  increasing  the  lines  of  force  that  are  cut  by  the 
coils  of  wire. 

111.  Low  and  High  Tension  Magnetos. — A  "low  tension"  type  of 
magneto  is  one  which  delivers  current  of  a  low  voltage,  which  must  be 
converted  to  the  necessary  high  voltage  for  ignition  by  an  external 
transformer  coil.  The  armature  contains  only  a  primary  winding, 
while  the  transformer  coil  has  the  usual  primary  and  secondary  windings. 


FIG.  177. — Side  view — Remy  Model  P  magneto. 

A  "high  tension"  magneto  delivers  current  from  the  armature  of 
sufficiently  high  voltage  for  ignition,  without  the  use  of  an  external 
transformer  coil.  The  high  tension  current  is  generated  by  having  two 
windings  on  the  armature  of  the  magneto,  one  a  primary  winding,  and 
the  other  a  secondary  winding.  The  armature  assembly  also  contains  a 
condenser.  The  true  high  tension  magneto  must  not  be  confused  with 
the  so-called  high  tension  magnetos  in  which  the  armature  current 
is  transformed  by  a  coil  merely  placed  in  the  top  of  the  magneto,  instead 
of  outside  as  is  done  in  the  low  tension  type.  The  coil  is  merely  con- 
tained in  the  magneto  assembly  for  convenience  but  this  does  not  make 
it  a  "high  tension"  magneto  in  the  strict  sense  of  the  term. 

112.  Armature  and  Inductor  Types. — :An  "armature"  type  of 
magneto  is  one  in  which  the  lines  of  force  are  cut  by  means  of  a  coil  of 


MAGNETOS  AND  MAGNETO  IGNITION 


157 


wire  wound  on  an  armature  rotating  between  the  magnetic  pole  pieces, 
as  just  described.     It  may  be  either  of  the  high  or  low  tension  type. 

In  an  "inductor"  type  of  magneto,  the  coil  of  wire  is  stationary. 
The  cutting  of  the  lines  of  force  by  the  stationary  coil  is  caused  by  a 
revolving  "inductor."  The  current  is  generated  in  the  stationary  coil 
and  this  avoids  the  necessity  of  having  sliding  contacts  and  brushes  in 
order  to  connect  the  coil  with  the  external  circuit.  The  inductor  type 
may  also  be  "low"  or  "high"  tension.  The  constructional  features 
of  these  two  general  types  will  be  pointed  out  in  considering  the  several 
modern  magneto  types. 


FIG.  178.  —  Distributor  end  view  —  Remy  Model  P  magneto. 


113.  Remy  Model  P  Magneto.  —  Figures  177  and  178  show  side 
and  distributor  end  views  of  the  Remy  Model  P  magneto,  of  the  low 
tension  armature  type. 

The  Remy  armature  shown  in  Fig.  179  is  of  the  H  or  shuttle  type, 
with  laminated  core  made  from  soft  Norway  iron.  The  armature  heads 
are  of  hard  bronze,  and  the  drive  shaft,  which  is  of  steel,  is  cast  into  the 
armature  head.  The  armature  winding  is  of  cotton  covered  enameled 
wire  heavily  impregnated  with  a  special  insulating  compound  rendering 
it  impervious  to  heat  and  moisture.  The  armature  shaft  revolves  on 


158  THE  GASOLINE  AUTOMOBILE 

magneto-type  ball  bearings  which  are  made  dust  and  grit  proof  by  the 
use  of  felt  washers. 

In  a  low  tension  magneto,  the  current  generated  in  the  armature  is  led 
through  a  circuit  breaker  to  the  primary  winding  of  the  coil.  When  the 
circuit  breaker  is  closed,  the  current  flows  through  the  primary  winding 
and  magnetizes  the  core  of  the  coil.  At  the  desired  instant  for  the 
spark,  the  circuit  breaker  opens  the  circuit  quickly  and  thus  destroys  the 
magnetism  of  the  core  of  the  coil.  This  action  induces  a  high  tension 
current  in  the  secondary  winding  of  the  coil.  This  is  led  back  to  the 
distributor  of  the  magneto,  where  it  is  directed  to  the  proper  spark  plug 
on  the  engine. 

The  armature  winding  cuts  the  lines  of  force  twice  in  each  revolution 
and  therefore  will  give  two  sparks  per  revolution.  For  this  reason,  there 
are  two  lobes  on  the  cam  which  operates  the  circuit  breaker.  For  a  four- 
cylinder  engine,  the  magneto  armature  should  run  at  crank  shaft  speed, 
as  two  sparks  are  required  per  revolution  of  the  engine.  For  a  six- 
cylinder  engine,  the  armature  of  the  magneto  should  run  at  one  and  one- 
half  times  crank  shaft  speed,  as  three  sparks  are  needed  per  revolution  of 
the  engine.  The  distributor"  terminals  should  be  connected  to  the  plugs 
in  the  order  in  which  the  cylinders  are  to  fire. 

The  Circuit  Breaker. — The  circuit  breaker  illustrated  in  Fig.  180  may 
be  shifted  by  the  spark  lever  to  change  the  time  of  the  spark.  The 
breaker  points  are  made  of  iridium-platinum,  which  gives  them  an 
exceedingly  long  life.  The  timing  control  lever  may  be  located  on  either 
side  of  the  magneto,  as  the  circuit  breaker  and  housing  are  reversible. 
An  ample  timing  range  of  35°  is  provided  for. 

Condenser. — The  condenser,  instead  of  being  placed  in  the  coil,  is 
placed  just  above  the  armature.  The  purpose  of  the  condenser  is  to 
prevent  sparking  at  the  breaker  points,  when  they  break  the  magneto 
primary  circuit. 

Magnets. — The  magnets  are  made  from  tungsten-steel  specially 
heat  treated  and  hardened,  thereby  insuring  the  retention  of  magnetism 
for  a  long  period. 

Coil. — The  coil,  the  top  view  of  which  is  seen  in  the  wiring  diagram  of 
Fig.  181,  has  the  switch  built  integral  with  it.  The  coil  is  fastened 
behind  the  dash  and  the  switch  face  only  appears  on  the  driving  side. 

Distributor  and  Timing  Button. — The  distributor  terminals  located  on 
the  face  of  the  distributor  provide  a  reliable  method  of  securing  the  high 
tension  spark  plug  cables.  An  ingenious  device,  known  as  the  timing 
button,  is  incorporated  in  the  distributor,  for  the  purpose  of  timing  the 
magneto  to  the  motor.  With  this  device  the  circuit  breaker  and  dis- 
tributor are  brought  into  proper  position,  thus  facilitating  this  usually 
difficult  operation  of  timing  the  magneto  to  the  motor,  an  operation  that 
frequently  puzzles  even  an  experienced  repair  man. 


MAGNETOS  AND  MAGNETO  IGNITION 


159 


FIG.  179. — Armature  of  Remy  Model  P  magneto. 


FIG.  180. — Remy  Model  P  magneto — circuit  breaker  removed. 


FIG.  181. — Wiring  diagram  for  Remy  Model  P  magneto. 


160  THE  GASOLINE  AUTOMOBILE 

For  timing  the  magneto,  turn  the  engine  over  by  the  starting  crank 
until  No.  1  piston  reaches  the  top  dead  center  at  the  end  of  the  com- 
pression stroke.  Press  in  on  the  timing  button  at  the  top  of  the  dis- 
tributor and  turn  the  magneto  shaft  until  the  plunger  of  the  timing 
button  is  felt  to  drop  into  the  recess  on  the  distributor  gear.  This  places 
both  distributor  and  circuit  breaker  in  the  proper  position  correspond- 
ing to  the  engine  position  given  above,  and  they  may  now  be  coupled 
together. 

114.  The  Connecticut  Magneto. — This  magneto,  illustrated  in  Fig. 
182,  likewise  has  a  shuttle  wound  armature  revolving  between  the 
poles  of  permanent  magnets,  and  generates  an  alternating  low  ten- 
sion current  with  two  impulses  for  each  revolution.  It  has  but  a  single 


FIG.  182. — Connecticut  magneto  partially  disassembled. 

primary  wire  running  to  the  switch;  all  secondary  wires  connect  from 
the  magneto  direct  to  the  plugs.  The  transformer  coil  is  encased  in 
a  metal  tube  in  cartridge  form  and  is  mounted  in  the  magneto  just  above 
the  armature. 

115.  Dual  Ignition  Systems. — The  voltage  generated  in  a  magneto 
depends  on  its  speed,  and  this  makes  it  desirable  to  have  some  other 
source  of  current  for  starting  an  engine.  This  auxiliary  source  is  either 
a  set  of  dry  cells  or  a  storage  battery.  In  the  dual  system  the  battery 
supplies  the  primary  current  for  starting,  the  current  being  led  through 
the  circuit  breaker  and  primary  winding  of  the  coil.  On  the  dual  system 
the  regular  coil  and  distributor  of  the  magneto  are  used.  After  the  engine 
is  started  the  switch  can  be  thrown  to  use  the  magneto  current. 


MAGNETOS  AND  MAGNETO  IGNITION 


161 


116.  Eisemann  High  Tension  Dual  Ignition. — The  wiring  diagram 
for  the  Eisemann  E.  M.  Dual  system  is  shown  in  Fig.  183.  This  magneto 
is  of  the  high  tension  armature  type.  The  Eisemann  dual  system  consists 
of  a  direct  high  tension  magneto  and  a  combined  transformer  coil  and 
switch,  the  transformer  being  used  only  in  connection  with  the  battery, 
and  the  switch  being  used  in  common  by  both  battery  and  magneto  systems. 
The  magneto  is  practically  the  same  as  a  single  ignition  high  tension 
instrument.  To  insure  reliability,  the  vulnerable  parts  of  each  system 
are  separate  from  those  of  the  other.  For  instance,  separate  windings 
and  circuit  breakers  are  used  for  each  system.  On  the  other  hand,  parts 


FIG.    183. — Wiring    diagram — Eisemann  type  E.    M.   Dual    four-cylinder   ignition 

system. 

that  are  not  subject  to  accident  or  rapid  wear  are  used  in  common,  so  as 
to  avoid  unnecessary  duplication. 

The  magneto  armature  is  an  iron  core,  made  of  many  pieces  of  soft 
sheet  iron  riveted  together,  around  which  is  a  primary  winding  of  medium- 
gauge  copper  wire.  Over  this  primary  winding,  is  a  secondary  winding 
consisting  of  many  coils  of  very  fine  copper  wire,  the  wire  being  specially 
insulated  in  the  entire  length  and  the  layers  being  carefully  insulated 
from  each  other.  The  low  tension  current,  formed  by  rotating  the  arma- 
ture, in  turn  induces  a  secondary  or  high  tension  current  in  the  secondary 
winding.  The  transformation  of  the  low  tension  current  into  high  ten- 
sion current  is  obtained  by  suddenly  interrupting  the  low  tension  current 


162 


THE  GASOLINE  AUTOMOBILE 


by  the  circuit  breaker  or  make-and-break  mechanism .  It  will  thus  be  seen 
that  the  high  tension  armature  is  practically  a  transformer  coil  wound 
directly  on  the  armature  core  with  a  circuit  breaker  to  interrupt  the 
primary  current. 

Spark  Control— As  the  spark  occurs  when  the  primary  circuit  is 
broken  by  the  opening  of  the  platinum  contacts,  the  timing  of  the  spark 
can,  therefore,  be  controlled  by  having  these  platinum  contacts  open 
sooner  or  later.  This  latter  is  accomplished  by  the  angular  movement  of 
the  timing  lever  body.  This  movement  gives  a  timing  range  of  30°. 
The  spark  is  fully  retarded  when  the  timing  lever  is  pushed  as  far  as 
possible  in  the  direction  of  rotation  of  the  armature  and  is  advanced 
when  pushed  in  the  opposite  direction. 

Safety  Spark  Gap. — If  a  spark  plug  cable  becomes  disconnected  or 
broken,  or  should  the  gap  in  the  spark  plug  be  too  great,  then  the  second- 
ary current  has  no  path  open  to  it  and,  in  endeavoring  to  find  a  circuit, 


FIG.  184. — Eisemann  armature  with  automatic  spark  advance  mechanism. 

will  sometimes  puncture  the  insulation  of  the  armature  or  of  the  coil. 
To  obviate  this,  a  so-called  "safety  spark  gap"  is  placed  on  the  top  of 
the  armature  dust  cover.  It  consists  of  projections  of  brass  with  a  gap 
between. them.  One  of  these  is  an  integral  part  of  the  dust  cover,  and 
therefore  forms  a  ground. 

The  Coil. — The  coil  of  Fig.  183  is  designated  as  Type  D  C  and  consists 
of  a  non-vibrating  transformer  and  a  switch  which  is  used  in  common 
to  put  either  the  battery  or  magneto  ignition  into  operation.  The  coil 
is  cylindrical  in  shape,  is  compact,  and  is  placed  through  the  dashboard. 
The  end  which  projects  through  on  the  same  side  as  the  motor  has. 
terminal  connections  for  the  tables.  The  other  end,  facing  the  operator, 
contains  the  switch  and  the  starting  mechanism.  The  transformer  coil 
is  used  only  in  conjunction  with  the  battery.  There  is  a  push  button 
circuit  breaker  in  the  center  of  the  switch  for  producing  a  spark  with 
the  battery  current  when  the  engine  is  not  running.  The  coil  is  provided 
with  a  lock  and  key,  so  that  the  switch  may  be  locked  in  the  "off" 
position. 


MAGNETOS  AND  MAGNETO  IGNITION  163 

117.  Eisemann  Automatic   Spark   Control. — The    automatic    spark 
control  magneto  is  of  the  same  construction  as  the  standard  high-tension 
instrument  with  the  addition  of  the  automatic  mechanism  as  shown  in 
Fig.  184.     The  automatic  advance  is  accomplished  by  the  action  of 
centrifugal  force  on  a  pair  of  weights  attached  to  one  end  of  a  spiral 
sleeve  between  the  shaft  of  the  magneto  and  the  armature.     When  the 
armature  is  rotated,  the  weights  begin  to  spread  and  exert  a  longitudinal 
pull  on  the  sleeve,  which  in  turn  changes  the  position  of  the  armature 
with  reference  to  the  pole  pieces,     In  this  way,  the  moment  of  greatest 
induction  is  advanced  or  retarded  and  with  it  the  break  in  the  primary 
circuit.     The  cams  which  lift  the  circuit  breaker  and  cause  the  break  in 
the  primary  circuit  are  fixed  in  the  correct  position  with  relation  to  the 
armature,  so  that  the  break  occurs  at  the  moment  when  the  current  in 
the  winding  is  strongest. 

118.  The  K-W  High  Tension  Magneto.— The  K-W  high  tension 
magneto  is  of  the  alternating  current  inductor  type.     Figure  185  is  an 
external  view  and  Fig.  186  shows  a  longitudinal  sectional  elevation.     By 
referring  to  the  numbers,  an  idea  can  be  obtained  of  the  function  of  the 
various  parts. 

64  Driving  pinion.  1  Bridge. 

79  Plunger  for  primary  circuit.  100  High  tension  lead. 

67  Cam.  96  Distributor  block. 

68  Cam  roller.  73  Magnets. 
189  Retainer  spring.  180  Rotor. 

56  Switch  binding  post.  114  Primary  winding. 

98  Distributor  brush  holder.  113  Secondary  winding. 

120  Secondary  contact  plunger.  126  Condenser. 

119  Secondary     distributor  118  Safety  spark  gap. 

plunger.  186  High  tension  bus  bar. 
2  Distributor  gear.  14  Low  tension  bus  bar. 

10  Base. 

The  only  revolving  part  in  the  K-W  magneto  is  shown  in  Fig.  187. 
This  part  is  the  rotor  which  is  constructed  of  fine  laminations  of  the 
softest  Norway  sheet  iron.  These  laminations  are  riveted  together, 
are  accurately  bored  out  to  fit  the  rotor  shaft,  and  are  accurately  ma- 
chined as  to  width  and  diameter,  being  mounted  on  this  shaft  at  exactly 
right  angles  to  each  other.  Between  these  two  pieces  is  the  stationary 
winding  or  coils,  also  shown  separately  in  Fig.  188.  The  winding,  which 
is  concentric  with  the  armature  shaft,  is  mounted  in  between  the  two 
halves  of  the  rotor  and  stands  absolutely  still.  In  the  position  shown, 
the  lines  of  force  go  straight  across  through  the  right  hand  rotor.  When 
the  shaft  turns  45°  from  this  position,  the  rotors  connect  the  magnetism 
from  one  pole  piece,  through  the  center  of  the  winding,  to  the  opposite 
pole  piece,  thus  giving  a  powerful  wave  of  current  from  a  quarter  revolu- 
tion of  the  magneto. 


164  THE  GASOLINE  AUTOMOBILE 

The  winding,  shown  in  Fig.  188,  is  a  double  winding,  that  is,  it  has  a 
primary  or  low  tension  winding,  which  is  surrounded  by  a  secondary  or 
high  tension  winding.  This  primary  winding  goes  to  the  circuit  breaker 
of  the  magneto,  where  its  current  is  interrupted  when  the  spark  is 


FIG.  185. — K-W  high  tension  magneto. 


/0 
FIG.  186. — Section  of  K-W  magneto. 

wanted  and  during  one  of  the  periods  of  armature  rotation  in  which  con- 
siderable current  is  generated. 

At  the  moment  of  this  interruption  of  current  in  the  primary,  a  power- 
ful surge  of  current  is  generated  in  the  secondary  winding.  The  current 
from  this  secondary  winding  goes  straight  up  through  the  hard  rubber 
terminal  to  the  high  tension  bus  bar,  as  shown  in  Fig.  186,  to  the  center 


MAGNETOS  AND  MAGNETO  IGNITION 


165 


of  the  distributing  brush*  and  from  there  is  distributed  to  the  various 
cylinders  of  the  motor. 

The  condenser,  No.  126,  Fig.  186,  is  bridged  across  the  circuit  breaker 
points.     Its  function  is  to  absorb  the  low  tension  current  after  the 


FIG.  187.— K-W  rotor  and  coils 


FIG.  189. — Wiring  diagram  for  K-W  high  tension  magneto. 

breaking  of  the  primary  circuit  at  the  breaker  points.     This  condenser 
is  made  of  a  large  number  of  sheets  of  tinfoil  and  mica. 


166 


THE  GASOLINE  AUTOMOBILE 


The  safety  gap,  No.  118,  Fig.  186,  is  a  necessary  part  of  any  high  tension 
magneto,  its  object  being  to  form  a  path  for  the  high  tension  current  to 
jump  through  incase  a  secondary  cable  that  leads  to  the  spark  plugs 
should  be  off  when  the  engine  is  running.  This  safety  gap,  as  its  name 
implies,  prevents  the  magneto  from  burning  out,  for  as  long  as  there  is  a 
path  for  the  high  tension  current  to  pass  through,  it  will  never  punc- 
ture the  insulation  of  the  secondary  winding. 

It  will  be  noted  by  referring  to  Fig.  186  that  the  distributor  shaft  is 
carried  on  two  ball  bearings,  as  is  also  the  rotor  shaft.  The  distributor 
block  is  moulded  from  a  special  composition  of  hard  rubber,  and  is  ac- 
curately machined  all  over.  The  brass  segments  that  connect  with  the 
various  plug  holes  on  top  of  the  distributor  are  moulded  into  the  hard 


FIG.  190. — Dixie  magnets  and  rotor.          FIG.  191. — Dixie  coil  and  field  pieces. 

rubber.  A  carbon  brush  is  mounted  in  the  distributor  arm,  which  presses 
slightly  against  the  distributor  segments,  and  the  interior  of  the  distributor 
is  practically  dust  and  moisture  proof,  being  protected  by  a  hard  rubber 
cover,  held  in  place  by  a  three-legged  spider  or  bridge,  No.  1 .  This  bridge 
also  carries  the  primary  circuit  to  the  circuit  breaker.  The  binding 
post,  No.  56,  is  the  point  from  which  the  switch  wire  is  run  to  the  switch 
for  the  purpose  of  cutting  out  the  circuit  breaker  and  stopping  the  engine. 

Figure  189  is  a  wiring  diagram  for  the  K-W  high  tension  magneto, 
Type  H. 

119.  The  Dixie  Magneto. — The  Dixie  magneto  is  built  upon  a  princi- 
ple different  from  that  of  either  the  armature  or  the  inductor  types. 
Figure  190  indicates  the  arrangement  of  the  magnets  and  the  rotating 
element  carried  in  bearings  by  the  two  pole  pieces.  This  rotor  turns 


MAGNETOS  AND  MAGNETO  IGNITION 


167 


between  the  pole  pieces  and,  as  the  iron  pieces  simply  form  extensions 
to  the  magnet  pole  pieces  and  are  always  of  the  same  polarity,  there  is 
no  reversal  of  magnetism  through  them. 

Just  above  the  rotor,  and  with  its  axis  at  right  angles,  is  placed  the 
coil,  supported  by  the  two  upright  field  pieces  enclosing  the  armature  as 
shown  in  Fig.  191.  Figures  192,  193,  194,  and  195  show  the  reversal  of  the 


FIG.  192.  FIG.  193.  FIG.  194.  FIG.  195. 

FIGS.  192  TO  195. — Showing  the  principle  of  the  Dixie  magneto. 

lines  of  force  through  the  coil  during  one-half  revolution  of  the  rotor. 
This  change  of  the  lines  of  force  through  the  coil,  which  has  a  primary  and 
a  secondary  winding,  causes  a  low  tension  alternating  current  in  the 
primary  winding,  and  this  induces  the  high  tension  current  in  the  secondary 
winding  when  the  contact  points  break  the  primary  circuit.  Figure  196 
is  a  diagrammatic  sketch  of  the  primary  circuit.  P  is  the  primary  coil,  A 


FIG.  196. — Primary  circuit  of  Dixie  magneto. 


FIG.  197. — Bosch  high  tension 
magneto. 


is  the  core,  R  is  the  condenser,  X  and  Y  are  the  circuit  breaker  points,  G 
is  the  common  ground  connection  for  both  primary  and  secondary  wind- 
ings, and  S  is  the  secondary  coil. 

120.  The  Bosch  High  Tension  Magneto.— The  Bosch  magneto, 
shown  in  Fig.  197,  is  of  the  high  tension  armature  type,  generating  two 
sparks  during  each  revolution  of  the  armature  shaft.  A  longitudinal 


168  THE  GASOLINE  AUTOMOBILE 

section  of  a  Bosch  magneto  is  shown  in  Fig.  198  and  a  rear  view  in  Fig. 
199.     The  principal  numbered  parts  are  as  follows: 

1  Brass  plate  at  the  end  of  the  primary  winding. 

2  Fastening  screw  for  contact  breaker. 

119  Long  platinum  contact  screw. 
118  Short  platinum  contact  screw. 

9  Condenser. 

120  Lock  nut  for  contact  screw  119. 

121  Flat  spring  for  magneto  interrupter  lever. 
105  Holding  spring  for  interrupter  cover. 

10  High  tension  collector  ring. 

11  Carbon  brush  for  high  tension  current. 

12  Holder  for  brush. 

13  Fastening  nut  for  brush  holder. 


FIG.  198. — Section  of  Bosch  high  tension  magneto. 

14  Spring  contact  for  conducting  the  high  tension  current. 

15  Distributor  brush  holder. 

16  Distributor  carbon  brush. 

17  Distributor  disc. 

18  Central  distributor  segment. 
20  High  tension  terminals. 

22  Dust  cover.    . 
123  Interrupter  lever. 

168  Interrupter  housing  and  timing  lever. 

169  Cover  for  interrupter  housing. 
173.  Low  tension  brush. 

The  beginning  of  the  primary  winding  is  grounded  to  the  armature 
core  and  the  other  end  is  connected  to  the  brass  plate  1.  In  the  center 
of  this  plate  is  the  fastening  screw  2,  which  serves  first,  for  holding  the 
contact  breaker  in  its  place,  and  second,  for  conducting  the  primary  cur- 
rent to  the  platinum  screw  block  of  the  contact  breaker.  Screw  2  is  insu- 


MAGNETOS  AND  MAGNETO  IGNITION 


169 


lated  from  the  contact  breaker  disc,  which  is  in  metallic  connection  with  the 
armature  core.  The  platinum  screw  119  is  fixed  in  the  contact  piece 
and  receives  the  current  from  screw  2.  Pressed  against  this  platinum 
screw,  by  means  of  the  spring  shown,  is  the  magneto  interrupter  lever  123 
with  platinum  screw  118,  which  is  connected  to  the  armature  core  and, 
therefore,  with  the  grounded  end  of  the  primary  winding.  The  primary 
circuit  is,  therefore,  closed  as  long  as  the  magneto  interrupter  lever  123 
is  in  contact  with  platinum  screw  119.  The  circuit  is  interrupted  when 
the  lever  is  rocked  by  the  cam  so  as  to  open  the  contact.  The  condenser 
9  is  connected  across  the  gap  formed  when  the  contacts  break. 

The  beginning  of  the  secondary  winding  is  connected  to  the  insulated 
end  of  the  primary  so  that  the  one  forms  a  continuation  of  the  other. 
The  other  end  of  the  secondary  winding  leads  to  the  collector  ring  10, 


20 


20 


FIG.  199. — End  view  of  Bosch  high  tension  magneto. 

on  which  slides  a  carbon  brush  11,  held  by  the  carbon  holder  12,  and  thus 
insulated  from  the  magneto  frame.  From  the  brush  11  the  secondary 
current  is  conducted  to  the  terminal  13,  through  the  spring  connection 
14  to  the  center  distributor  contact  18,  and  from  there  to  the  carbon 
brush  16,  the  latter  rotating  with  the  distributor  gear  wheel. 

In  the  distributor  disc  17,  metal  segments  are  embedded,  and  as  the 
carbon  brush  16  rotates,  it  makes  contact  with  the  respective  segments  of 
the  distributor.  Attached  to  the  metal  segments  of  the  distributor  are 
the  connection  terminals  20  to  which  are  fixed  the  conducting  cables  to  the 
spark  plugs. 

From  the  end  of  the  secondary  winding  the  high  tension  current  is 
distributed  to  the  respective  cylinders  in  the  order  in  which  they  operate. 
The  current  produces  the  spark  which  causes  the  explosion;  it  then 
returns  through  the  motor  frame  and  the  armature  core  back  to  the  be- 

18 


170 


THE  GASOLINE  AUTOMOBILE 


ginning  of  the  secondary  winding.     The  diagram  of  connections  is  shown 
in  Fig.  200. 

Safety  Spark  Gap. — In  order  to  protect  the  insulation  of  the  armature 
and  of  the  current  conducting  parts  of  the  apparatus  against  excessive 
voltage,  a  safety  spark  gap  is  provided  as  shown  in  Fig.  200.  The  current 
will  pass  through  this  gap  in  case  a  cable  is  taken  off  while  the  magneto 
is  in  operation  or  if  the  electrodes  on  the  spark  plugs  are  too  far  apart. 
The  discharges,  however,  should  not  be  allowed  to  pass  through  the 
safety  gap  for  any  length  of  time;  special  care  has  to  be  taken  in  this 
respect  if  the  motor  is  equipped  with  a  second  system  of  ignition,  in 


INTERRUPIOfl  MS 


»  FIG.  200. — Wiring   diagram   of   Bosch   high   tension  magneto. 

which  case  it  is  necessary  to  short  circuit  the  primary  winding,  as  the 
continued  discharge  of  the  current  over  the  safety  gap  is  likely  to  damage 
the  magneto. 

121.  The  Bosch  Dual  System.— In  the  Bosch  dual  ignition  system, 
the  standard  type  of  Bosch  magneto  is  used  with  the  application  of  two 
timers  or  interrupters.  The  parts  of  the  regular  current  interrupter  are 
carried  on  a  disc  that  is  attached  to  the  armature  and  revolves  with  it, 
the  rollers  or  segments  that  serve  as  cams  being  supported  on  the  inter- 
rupter housing.  In  addition,  the  magneto  is  provided  with  a  steel  cam 
which  is  built  into  the  interrupter  disc  and  has  two  projections.  This 
cam  acts  on  a  lever  supported  by  the  interrupter  housing,  the  lever 
3emg  so  connected  in  the  battery  circuit  that  it  serves  as  a  timer  to 
control  the  flow  of  battery  current.  These  parts  may  be  seen  in  Fig. 


MAGNETOS  AND  MAGNETO  IGNITION 


171 


-HIGH    TENSION    CONNECTION 


FIG.  201. — Bosch  dual  system,  showing  magneto  interrupter  and  battery  timer. 


FIG.  202. — Wiring  diagram  for  Bosch  dual  system. 


172  THE  GASOLINE  AUTOMOBILE 

201.     A  non-vibrating  transformer  coil  is  used  with  the  battery  current 
to  produce  the  necessary  voltage. 

It  is  obvious  that  the  sparking  current  from  the  battery  and  from 
the  magneto  can  not  be  led  to  the  spark  plugs  at  the  same  time,  so  a 
further  change  from  the  magneto  of  the  independent  form  is  found  in 
the  removal  of  the  direct  connection  between  the  collecting  ring  and 
the  distributor.  The  collecting  ring  brush  shown  in  Fig.  198  as  No.  11 
and  in  Fig.  202  as  No.  3,  is  instead,  connected  to  the  switch,  and  a  second 
wire  leads  from  the  switch  to  the  central  terminal  on  the  distributor. 
When  running  on  the  magneto,  the  sparking  current  that  is  induced  in 
the  secondary  armature  winding  flows  to  the  distributor  by  way  of  the 
switch  contacts.  When  running  on  the  battery,  the  primary  circuit  of 
the  magneto  is  grounded,  and  there  is,  therefore,  no  production  of  spark- 
ing current  by  the  magneto;  it  is  then  the  sparking  current  from  the 


Fio.  203.— Parts  of  Bosch  dual  coil. 

coil  that  flows  to  the  central  distributor  connection.  It  will  thus  be 
seen  that  of  the  magneto  and  battery  circuits  the  only  parts  used  in 
common  are  the  distributor  and  the  spark  plugs. 

The  Bosch  Dual  Coil. — The  Bosch  dual  coil  used  in  the  dual  system 
consists  of  a  cylindrical  housing  bearing  a  brass  casting,  the  flange  of 
which  serves  to  attach  the  coil  to  a  dashboard  or  other  part.  The  coil 
is  provided  with  a  key  and  lock,  by  which  the  switch  may  be  locked  when 
in  the  "  Off"  position.  This  is  a  point  of  great  advantage,  for  it  makes  it 
unlikely  that  the  switch  will  be  left  thrown  to  the  battery  position  when 
the  engine  is  brought  to  a  stop.  The  absence  of  such  an  attachment  is 
responsible  in  a  large  measure  for  the  accidental  running  down  of  the 
battery.  This  locking  device  also  prevents  the  unauthorized  operation 
of  the  engine.  The  parts  of  the  coil  are  shown  in  Fig.  203.  In  addition 


MAGNETOS  AND  MAGNETO  IGNITION  173 

to  the  housing  and  end  plate,  they  consist  of  the  coil  itself,  the  stationary 
switch  plate,  and  the  connection  protector. 

When  the  engine  is  running  on  battery  ignition,  a  single  contact 
spark  is  secured  at  the  instant  when  the  battery  interrupter  breaks 
its  circuit,  and  the  intensity  of  this  spark  permits  efficient  operation  of 
the  engine  on  the  battery  system. 

Starting  on  the  Spark. — For  the  purpose  of  starting  on  the  spark,  a 
vibrator  may  be  cut  into  the  coil  circuit  by  turning  the  button  that  is 
seen  on  the  coil  body  in  Figs.  202  and  203.  Normally,  this  vibrator 
is  out  of  circuit,  but  the  turning  of  the  button  places  it  in  the  battery 
primary  circuit  instead  of  the  circuit  breaker  on  the  magneto.  A 
vibrator  spark  of  high  frequency  is  thus  produced. 

It  will  be  found  that  the  distributor  on  the  magneto  is  then  in  such 
a  position  that  this  vibrator  spark  is  produced  at  the  spark  plug  of  the 
cylinder  that  is  performing  the  power  stroke;  if  mixture  is  present  in 
this  cylinder,  ignition  will  result  and  the  engine  will  start. 

Connections. — In  the  wiring  diagram  of  this  system  as  shown  in  Fig. 
202,  it  will  be  noted  that  while  the  independent  magneto  requires  but  one 
switch  wire  in  addition  to  the  cables  between  the  distributor  and  spark 
plugs,  the  dual  system  requires  four  connections  between  the  magneto 
and  the  switch;  two  of  these  are  high  tension  and  consist  of  wire  No.  3 
by  which  the  high  tension  current  from  the  magneto  is  led  to  the  switch 
contact,  and  wire  No.  4  by  which  the  high  tension  current  from  either 
magneto  or  coil  goes  to  the  distributor.  Wire  No.  1  is  low  tension, 
and  conducts  the  battery  current  from  the  primary  winding  of  the  coil 
to  the  battery  interrupter.  Low  tension  wire  No.  2  is  the  grounding 
wire  by  which  the  primary  circuit  of  the  magneto  is  grounded  when  the 
switch  is  thrown  to  the  off  or  to  the  battery  position.  Wire  No.  5  leads 
from  the  negative  terminal  of  the  battery  to  the  coil,  and  the  positive 
terminal  of  the  battery  is  grounded  by  wire  No.  7;  a  second  ground  wire 
No.  6  is  connected  to  the  coil  terminal. 

122.  Bosch  Two -independent  System. — The  Bosch  two-independent 
or  double  system  consists  of  two  complete  and  independent  systems  of 
ignition.  One  consists  of  a  Bosch  high  tension  magneto  system  and  the 
other  of  a  Bosch  high  tension  distributor  battery  system. 

The  battery  system  is  utilized  for  starting  purposes  and  for  emergency 
ignition  in  case  of  accident  to  the  magneto  system,  which  is  used  for 
ordinary  service.  The  battery  system  consists  of  a  combined  coil  and 
switch  and  a  timer-distributor,  which  are  completely  independent  of  the 
magneto.  The  two  systems  are  brought  together  at  the  switch,  and  the 
connections  are  such  that  the  engine  may  be  operated  on  the  magneto 
with  one  set  of  plugs,  or  on  the  battery  with  the  other  set  of  plugs, 
or  on  the  magneto  and  battery  together,  in  which  case  both  sets  of 


174 


THE  GASOLINE  AUTOMOBILE 


plugs  are  used.  Either  the  battery  or  magneto  may  be  used  for  ignition 
with  the  other  system  entirely  dismantled  or  removed  from  the  engine. 
The  wiring  diagram  for  this  system  is  shown  in  Fig.  204. 

123.  The  Ford  Magneto  and  Ignition  System. — The  magneto  which 
generates  the  current  for  the  ignition  system  in  the  Ford  car  is  of  the  low 
tension  alternating  current  type  and  differs  from  the  conventional  type 
in  that  the  stationary  and  revolving  elements  are  interchanged. 

The  Ford  magneto,  as  shown  in  Fig.  205,  has  but  two  parts,  a  sta- 
tionary armature,  consisting  of  a  number  of  coils,  which  are  attached 
to  a  stationary  support  in  the  flywheel  housing,  and  a  set  of  permanent 
field  magnets  of  the  horseshoe  type,  which  are  secured  to  the  flywheel, 
the  whole  being  a  part  of  the  motor.  The  magnets  revolve  with  the 
flywheel  at  a  distance  of  ^2  m-  from  the  coils,  in  which  the  current  is 


FIG.  204. — Wiring  diagram  for  Bosch  two-independent  system. 


induced  by  the  magnetic  field.  The  current  flows  to  the  four  spark  coils, 
passing  through  whichever  one  is  at  the  instant  connected  to  the  ground 
by  the  commutator.  The  coils  are  the  ordinary  double  winding  vibra- 
tor coils.  ^  The  induced  current  from  each  coil  goes  to  its  spark  plug  to 
perform  its  function  of  igniting  the  charge.  The  magneto  and  its 
component  parts  are  fully  illustrated  in  Fig.  206. 

The  diagram  of  Fig.  207  shows  the  plan  of  wiring  of  the  Ford  Model 
T  motor,  which,  it  will  be  noted,  is  very  simple.  The  current  generated 
by  the  magneto  flows  through  the  primary  winding  of  the  coil  whose 
circuit  is  closed  by  the  commutator,  to  the  commutator,  and  back  through 
the  frame  of  the  motor  to  the  magneto.  This  completes  the  primary 


MAGNETOS  AND  MAGNETO  IGNITION 


175 


circuit  or  path  of  the  magneto  current.  The  high  tension  induced  in 
the  secondary  winding  of  the  coils  is  led  to  the  spark  plugs  in  the  cylinders 
as  their  respective  primary  circuits  are  completed  by  the  commutator. 

Magneto  Coil  Spoof 

Copper  Wire 

End  of  Ribbon  1 
Grounded  Here  J 

To  Coil 

Magneto  Coil  Support 


FIG.  205.— The    Ford   magneto. 

124.  Magneto  Speeds. — Nearly  all  of  the  modern  magnetos  are  con- 
structed, as  was  pointed  out  in  Art.  113,  page  157,  to  give  one  spark  for 
each  one-half  revolution  of  the  armature  or  inductor.  This  means  that 


FIG.  206. — Diagram  showing  the  course  of  circuit  through  the  Ford  ignition  circuit. 

for  each  revolution,  two  sparks  are  obtained  from  the  magneto.  For  a 
four-cylinder  four-stroke  engine,  there  are  two  explosions  per  revolution 
of  the  crank  shaft.  We  see,  therefore,  that  the  magneto  and  engine 


176 


THE  GASOLINE  AUTOMOBILE 


crank  shaft  must  run  at  the  same  speed.  For  a  six-cylinder  four-stroke 
engine,  there  are  three  explosions  per  revolution  of  the  crank  shaft,  re- 
quiring one  and  one-half  revolutions  of  the  magneto.  The  magneto 
must,  therefore,  run  one  and  one-half  times  the  crank  shaft  speed.  Some 
magnetos  are  built  to  give  four  sparks  per  revolution.  These  must,  of 
course,  be  set  to  run  at  one-half  the  speeds  given  above. 

125.  Timing  the  Magneto. — Necessarily,  the  rules  for  setting  and 
timing  magnetos  must  be  very  general.  If  the  magneto  has  been  removed 
or  is  out  of  adjustment,  the  engine  should  be  cranked  until  the  No.  1 
piston  (the  one  next  the  radiator)  is  on  dead  center  at  the  end  of  the 
compression  stroke.  This  position  can  usually  be  found  by  markings  on 
the  flywheel.  On  some  engines  the  manufacturers  recommend  that  the 
engine  be  cranked  just  a  few  degrees  past  the  dead  center.  The  position 
will  then  be  the  firing  position  for  the  No.  1  cylinder. 


Magneto 
Contact  Terminal 


Commutator  Wires 
and  Loom. 

FIG.  207. — Wiring  of  the  Ford  ignition  system. 

The  distributor  housing  should  then  be  taken  off  and  access  gained 
to  the  distributor  mechanism.  It  should  also  be  determined  just  which 
cylinder  corresponds  to  each  of  the  distributor  points.  The  armature 
should  then  be  rotated  until  the  distributor  segment  comes  in  contact 
with  the  distributor  point  for  No.  1  cylinder.  Adjust  the  armature  so 
that  the  contact  points  just  break  when  the  interrupter  housing  is  in  full 
retard  and  attach  it  to  the  driving  shaft.  The  spark  control  rod  should 
now  be  connected  and  adjusted  so  that  the  contact  points  just  open,  when 
the  spark  lever  on  the  steering  wheel  is  in  full  retard.  This  permits  the 
maximum  spark  advance. 


MAGNETOS  AND  MAGNETO  IGNITION  177 

126.  Battery  vs.  Magneto  Ignition. — It  is  a  somewhat  common  idea 
that  an  engine  will  run  faster  on  a  magneto  spark  than  on  a  battery  spark. 
This  contention  has  been  frequently  advanced  in  support  of  magneto 
ignition.     Extensive  experiments  on  engines  equipped  with  a  double 
system,  one  a  magneto  and  the  other  a  battery  system,  prove  that  with  the 
same  spark  setting,  there  is  practically  no  variation  in  engine  speed, 
provided  both  systems  are  in  perfect  order  and  adjustment.     In  in- 
dividual cases  where  the  contrary  has  been  found  it  was  probably  due  to 
some  weakness  or  defect  in  the  system  which  was  replaced  and  should 
not  be  taken  as  condemning  that  type  of  ignition  in  general. 

127.  General  Suggestions  on  Magnetos. — The  magneto  should  never 
be  tested  unless  the  whole  system  is  completely  assembled  with  all  parts 
and  wires  in  place  and  attached.       Water  should  be  kept  away  from  all 
parts  of  the  ignition  system.     Magnetos  were  not  intended  to  be  run  in 
water. 

Care  should  be  taken  when  oiling  parts  of  the  magneto.  A  small 
amount  of  oil  properly  placed  is  essential,  but  a  great  lot  on  everything 
is  a  constant  source  of  trouble. 

Don't  take  the  magneto  apart  or  try  to  improve  its  construction. 
Repairing  a  magneto  is  an  expert's  work.  Unless  you  are  one,  don't 
attempt  it. 

128.  Common  Magneto  Ignition  Definitions. — Low  Tension  Magneto. 
— A  magneto  which  generates  a  low  voltage  current,  requiring  a  trans- 
former coil  to  raise  the  voltage  for  ignition  purposes.     Only  one  wind- 
ing is  found  on  the  armature. 

High  Tension  Magneto. — One  which  generates  current  of  high  enough 
voltage  for  ignition  purposes.  The  armature  contains  two  windings, 
a  primary  and  a  secondary  winding.  No  outside  coil  is  necessary. 

Armature  Type  Magneto. — One  in  which  the  current  is  generated  by 
a  coil  of  wire  wound  around  a  core  revolving  between  the  poles  of  a 
permanent  magnet. 

Inductor  Type  Magneto. — A  type  of  magneto  in  which  the  coil  is 
stationary  and  the  lines  of  force  through  the  coil  are  changed  in  direction 
by  means  of  a  rotating  inductor. 

Dual  System  of  Ignition. — A  system  of  ignition  with  two  sources  of 
current,  magneto  and  battery,  either  of  which  may  be  used.  There  is 
practically  no  duplication  of  equipment,  as  the  magneto  timer,  distributor 
and  plugs  are  used  for  both  sources  of  current. 

Double  System  of  Ignition. — Two  complete  systems  of  ignition  with 
nothing  in  common  excepting  the  switch  on  the  dashboard.  There 
is  a  duplication  of  practically  the  entire  equipment,  plugs,  timer,  and 
distributor. 


CHAPTER  VIII 
STARTING  AND  LIGHTING  SYSTEMS 

129.  Starting  on  the  Spark. — If  an  engine  is  stopped  with  an  explosive 
mixture  in  the  cylinder,  it  may  sometimes  be  started  from  rest  by  merely 
causing  a  spark  in  the  cylinder.  In  a  four-stroke  engine  having  four  or 
more  cylinders  there  will  always  be  one  cylinder  on  the  expansion  stroke 
and  one  on  the  compression  stroke.  On  a  four-cylinder  automobile 
we  can  sometimes  swing  the  spark  lever  so  as  to  cause  a  spark  in  one  of 
these  cylinders,  and,  if  the  compression  has  not  been  lost  entirely,  or  the 
gasoline  vapor  has  not  been  condensed,  the  engine  will  start.  Sometimes 
an  engine  can  be  started  in  this  manner  after  standing  for  several  hours. 
To  make  an  engine  more  sure  of  starting  on  the  spark,  the  throttle 
should  be  opened  wide  before  the  engine  is  stopped.  This  will  insure  a 
good  charge  in  each  cylinder.  When  a  four-cylinder  motor  comes  to 
rest  after  the  spark  is  shut  off,  one  piston  will  be  on  its  exhaust  stroke  and 
another  will  be  on  its  suction  stroke,  both  of  these  cylinders,  therefore, 
being  open  to  the  air.  A  third  piston  will  be  on  its  compression  stroke 
with  all  valves  shut  and  the  fourth  will  be  going  down  on  the  expansion 
stroke  with  its  charge  still  fresh  because  the  current  has  been  turned  off. 
The  motor  will  come  to  rest  with  these  two  pistons  on  the  same  level, 
each  about  halfway  in  the  stroke.  To  start  the  motor,  turn  the  switch 
to  the  battery  side  and  press  the  ignition  starter  button.  Pressing  the 
ignition  starter  button  short-circuits  or  cuts  out  the  timer  or  circuit 
breaker  and  causes  current  to  flow  through  the  primary  winding  of  the 
coil.  Releasing  the  push  button  breaks  the  primary  circuit  and  causes  a 
high  tension  current  in  the  secondary  circuit,  which  will  be  conducted 
to  a  spark  plug  provided  the  distributor  arm  is  opposite  one  of  the 
distributor  segments. 

If  the  engine  comes  to  rest  with  the  piston  which  is  on  the  working 
stroke  on  the  same  level  with  the  piston  which  is  on  the  compression 
stroke,  the  distributor  arm  will  be  nearer  to  the  segment  leading  to  the 
cylinder  whose  piston  is  on  the  working  stroke.  If  the  spark  occurs  in 
this  cylinder  the  engine  will  be  run  in  the  desired  direction  and  if  the 
explosion  is  sufficient  to  carry  the  next  piston  over  the  top  of  the  com- 
pression stroke,  the  regular  cycles  will  be  continued;  but  if,  when  the 
engine  stops,  the  pistons  have  gone  beyond  the  position  where  they  are 
on  the  same  level,  the  spark  is  apt  to  occur  in  the  cylinder  which  is  on 

179 


18o  THE  GASOLINE  AUTOMOBILE 

the  compression  stroke.  This  explosion  will  drive  the  engine  backward. 
l^>ar  the  end  of  this  backward  stroke  the  inlet  valve  will  open  and  the 
burnt  gases  will  be  discharged  through  the  carburetor. 

If  the  engine  is  stopped  so  that  the  timer  points  or  circuit  breaker 
points  are  in  contact,  it  is  impossible  to  start  by  pressing  the  ignition 
starter  button,  but  starting  may  be  accomplished  by  retarding  the  spark 
control  lever  and  opening  and  closing  the  ignition  switch,  several  times  if 
necessary. 

The  same  method  of  starting  will  apply  to  two-  or  three-cylinder, 
two-stroke  engines.  If  a  two-stroke  engine  is  started  by  advancing  the 
spark,  the  motor  will  continue  to  run,  but  in  the  opposite  direction  from 
that  desired.  A  common  way  of  starting  a  single-cylinder  two-stroke 
engine  is  to  retard  the  spark  and  then  turn  the  engine  backward  by  hand 
until  the  spark  occurs.  The  engine  will  then  be  propelled  in  the  desired 
direction. 

The  failure  of  engines  to  start  on  the  spark  after  standing  for  some 
time  is  largely  due  to  the  gasoline  vapor  being  heavier  than  air.  After 
an  engine  has  stood  for  some  time  the  heavy  vapor  will  settle,  and,  if 
the  engine  is  cold,  the  gasoline  may  condense  on  the  piston  and  cylinder 
walls. 

130.  Mechanical  Starters. — Self  starters  may  be  divided  into  four 
general  types:  mechanical  starters,  air  starters,  acetylene  starters, and 
electric  starters. 

Mechanical  starters  include  the  various  types  of  hand  cranking 
devices  and  springs.  The  disadvantage  of  the  hand  cranking  starter  is 
that  it  requires  a  certain  amount  of  human  power.  The  only  advantage 
is  that  the  driver  does  not  have  to  leave  his  seat  to  crank  the  engine. 
The  spring  starter  is  capable  of  giving  the  engine  a  few  revolutions  only, 
and  if  the  engine  does  not  start  then,  it  becomes  necessary  for  the  driver 
to  wind  up  the  spring,  which  is  a  rather  tiresome  operation.  If  the 
motor  starts,  there  is  an  automatic  device  by  which  the  spring  is  wound 
up  by  the  engine. 

131.  Air  Starters. — In  the  air  starters,  the  air  is  pumped  into  a  storage 
tank  at  about  150  Ib.  pressure.     The  engine  is  started  by  admitting 
air  into  the  combustion  chamber.     The  pipe  leading  from  the  tank  goes 
to  a  distributor  which  is  driven  by  the  motor.     In  this  way  the  air  gets 
only  to  the  cylinder  which  is  on  the  working  stroke  and  has  all  the  valves 
closed.     This  system  has  the  disadvantage  that  the  air  is  liable  to  cool 
the  cylinder  and  prevent  proper  starting  of  the  regular  cycle  on  account 
of  the  gas  condensing  on  the  cool  walls. 

132.  Acetylene  Starters. — Some  manufacturers  have  equipped  their 
machines  with  a  device  for  starting  with  acetylene  gas.     This  gas  is 
very  explosive  and  will  ignite  readily  under  almost  any  conditions. 


STARTING  AND  LIGHTING  SYSTEMS  181 

These  engines  are  equipped  with  valves  and  tubes  from  the  acetylene 
lighting  system  so  that  the  driver  can  inject  a  small  quantity  of  acetylene 
gas  into  the  cylinders.  The  engine  will  then  be  practically  sure  of  start- 
ing on  the  spark.  This  system  has  been  largely  superseded  by  the 
electric  starter. 

133.  Electric  Starters. — A  still  further  development  in  this  line  is  the 
electric  starter.     Electric  starters  may  be  divided  into  three    types: 
first,  the  single-unit  system;  second,  the  two-unit  system;  and  third,  the 
three-unit  system.     In  the  first  system  the  motor-generator  unit  furnishes 
the  current  to  charge  the  storage  battery  and  operate  the  lights,  and 
also  acts  as  a  motor  in  cranking  the  engine.     The  two-unit    system 
has  a  generator  for  charging  the  battery  and  furnishing  the  current  for 
lighting  and  ignition,  but  it  has  a  separate  unit  (a  direct  current  motor) 
for  cranking  the  engine.     The  three-unit  system  has  a  generator  used 
solely  for  charging  the  battery  and  operating  the  lights,  a  motor  for 
cranking  the  engine  and  a  magneto  for  furnishing  current  for  ignition. 

In  all  electric  self-starters  it  is  necessary  to  have  a  storage  battery  to 
store  up  the  current  so  that  there  is  a  ready  source  of  sufficient  current  to 
drive  the  motor  for  starting.  The  units  of  the  self-starting  system  are: 
the  generator  to  furnish  electricity;  the  storage  battery  which  acts  as  a 
reservoir  to  hold  the  supply  of  current ;  and  an  electric  motor  to  crank  the 
engine.  The  electric  starter  may  be  directly  connected  to  the  gas  engine, 
or  it  may  be  driven  by  a  set  of  gears,  or  by  a  silent  chain. 

In  order  that  the  electric  motor  will  not  be  overspeeded  when  the 
engine  picks  up,  it  is  necessary  to  have  an  overrunning  clutch.  This 
device  operates  only  when  the  engine  runs  faster  than  the  motor.  The 
reduction  in  gears  between  the  electric  motor  and  the  engine  is  about  25 
to  1,  which  means  that  the  electric  motor  must  run  twenty-five  times  as  fast 
as  the  engine.  If  it  were  not  for  the  over-running  clutch,  the  electric  motor 
would  be  driven  at  excessively  high  speed,  when  the  engine  picks  up 
to,  say,  two  or  three  hundred  revolutions  per  minute.  The  over-running 
clutch  is  automatic.  It  permits  the  electric  motor  to  drive  the  engine,  but 
breaks  the  driving  connection  as  soon  as  the  engine  speeds  up  to  a 
higher  rate  than  the  motor  is  running  at.  In  the  one-unit  and  two-unit 
systems,  the  current  for  ignition  is  taken  from  the  storage  battery.  In 
all  cases  the  current  for  the  lights  comes  from  the  battery  when  the 
engine  is  running  at  low  speeds. 

There  is  also  another  type  of  self  starter  which  takes  the  place  of 
the  engine  flywheel.  This  unit  is  a  motor-generator  outfit  and  has  no 
reduction  gear  whatever. 

134.  Storage  Batteries. — A  commercial  storage  cell,  as  shown  in  Fig. 
208,  is  made  up  of  the  following  parts:  a  jar  or  container  usually  made 
of  rubber,  positive  and  negative  plates,  separators  between  the  plates,  and 


182 


THE  GASOLINE  AUTOMOBILE 


the  electrolyte.  The  electrolyte  is  a  solution  of  sulphuric  acid  and 
water.  After  the  plates  are  prepared,  they  are  placed  in  the  container 
and  the  electrolyte  added.  The  current  is  then  passed  through  the 
plates  and  solution.  In  this  manner  the  battery  is  charged.  When 
the  battery  is  fully  charged,  the  electrolyte  or  solution  in  the  cells  should 
have  a  specific  gravity  of  1.27  to  1.29.  The  specific  gravity  will  become 
lower  as  the  battery  discharges  and,  when  completely  discharged,  should 
not  be  lower  than  1.15  to  1.17,  or  about  twelve  points  less  than  when  fully 
charged.  Water  must  be  added  occasionally  to  replace  the  loss  by 
evaporation.  If  one  cell  regularly  requires  more  water  than  the  others, 
it  is  an  indication  of  a  leaky  jar.  A  leaky  jar  should  be  immediately 
replaced  by  a  new  one.  The  specific  gravity  of  the  electrolyte  is  the 


Expansion 
Chamber 


Sealing 
Compound 


Mud  Spaces 

•  FIG.  208.— Section  of  storage  cell. 

most  reliable  indication  of  the  state  of  charge  of  the  battery.  It  should 
never  go  below  1.15,  for  below  that  the  battery  will  not  have  sufficient 
power  to  turn  over  the  engine  and  it  will  not  burn  the  lights  so  as  to 
give  the  full  candle  power.  The  electrolyte  must  always  cover  the  plates. 
The  loss  by  evaporation  should  be  replaced  by  adding  pure  fresh  water. 
The  water  for  filling  the  batteries  must  be  either  distilled  water,  melted 
artificial  ice,  or  fresh  rain  water.  Never  add  acid.  The  batteries  should 
be  inspected  once  every  2  weeks  and,  if  the  electrolyte  is  below  the 
bottom  of  the  filling  tubes,  water  enough  should  be  added  to  bring  the 
level  up  to  the  proper  point.  Ordinarily  it  will  require  only  a  few  spoon- 
fuls. The  filling  plugs  must  be  replaced  and  screwed  up  tight  after 
filling.  Never  keep  the  supply  of  water  in  a  metal  container,  a  bucket  or 


STARTING  AND  LIGHTING  SYSTEMS  183 

can.  It  is  best  to  get  a  bottle  or  jug  of  distilled  water  from  your  druggist 
or  from  the  ice  plant.  The  main  point  is  to  keep  metal  particles  out  of 
the  battery.  Spring  water,  well  water,  or  hydrant  water  from  iron  pipes 
will  contain  iron  and  other  materials  in  solution  which  will  cause  trouble 
by  short  circuiting  the  plates. 

If  the  electrolyte  has  been  spilled  from  a  cell,  replace  the  loss  with 
new  electrolyte  and  follow  with  an  overcharge,  either  by  running  the 
engine  for  several  hours,  or  by  charging  from  an  outside  source.  In 
replacing  electrolyte,  have  the  specific  gravity  the  same  as  in  one  of  the 
adjacent  cells.  This  can  be  determined  by  use  of  the  hydrometer. 
When  new  electrolyte  is  required,  either  to  replace  loss  from  spilling,  or 
when  removing  the  sediment,  or  to  replace  a  broken  jar,  it  can  be  made 
by  mixing  chemically  pure  sulphuric  acid,  having  a  specific  gravity  of 
1.84,  and  distilled  water  in  the  proportions  of  1  part  of  acid  to  3  parts  of 
water,  by  volume.  The  acid  should  always  be  poured  into  the  water,  and 
not  the  water  into  the  acid.  A  glass,  or  other  acid-proof  vessel,  thor- 
oughly cleaned,  should  be  used  for  mixing  the  electrolyte.  When 
replacing  the  cell,  be  sure  that  the  positive  and  negative  connections 
have  the  same  positions  as  before.  Then  apply  vaseline  or  grease  to  the 
studs  and  nuts  before  making  the  connections. 

After  standing  for  some  time,  sediment  will  accumulate  in  the  bottom 
of  the  jar.  This  should  always  be  removed  before  it  reaches  the  bottom 
of  the  plates.  It  can  be  determined  by  inspection,  and  will  be  indicated 
by  lack  of  capacity,  excessive  evaporation  and  overheating  when 
charging.  If  the  battery  needs  repairing,  it  is  best  to  communicate  with 
the  manufacturers  who  will  advise  you  what  to  do.  The  battery  is  the 
heart  or  center  of  the  system.  The  electricity  generated  by  the  dynamo 
is  stored  in  the  battery,  and  is  used  by  the  starting  motor  to  crank  the 
engine,  and  for  the  lights  at  low  speed  and  when  the  engine  is  at  rest. 
When  the  current  flows  from  the  dynamo  through  the  battery  elements, 
it  is  termed  charging,  and  when  the  battery  is  supplying  current  for  crank- 
ing the  engine  or  to  the  lights,  it  is  termed  discharging. 

Immediately  upon  receipt  of  a  battery  or  new  automobile,  the  battery 
should  be  inspected.  Remove  the  vent  plugs.  See  that  the  battery 
plates  are  well  covered  with  solution,  and  if  it  is  not  up  to  the  inside  cover 
(see  Fig.  208)  add  distilled  water.  Filling  one  cell  does  not  fill  all  the 
cells.  The  battery,  if  neglected,  will  cause  the  entire  system  to  fail.  The 
starting  motor  may  operate  when  the  battery  is  weak,  but  the  battery 
life  is  thereby  shortened.  If,  however,  the  battery  is  kept  fully  charged, 
and  properly  supplied  with  pure  water,  it  will  give  uninterrupted  service. 
The  majority  of  car  owners  are  careless  about  giving  the  battery  the 
attention  it  should  have.  Remember  that  if  the  plates  are  exposed  (not 


184 


THE  GASOLINE  AUTOMOBILE 


covered  by  battery  solution)  they  become  sulphated  and  hard,  and  the 

battery  capacity  is  greatly  reduced. 

Specific  gravity  tests  are  made  with  the  hydrometer.     When  the 

battery  does  not  give  the  desired  results,  specific  gravity  tests  of  each  cell 
will  indicate  the  faulty  cell  or  cells.  Figure  209  shows  the 
ordinary  type  of  hydrometer  syringe  used  in  determining 
the  specific  gravities  of  solutions. 

The  action  of  this  hydrometer  is  similar  to  that  shown 
in  Fig.  95,  but  it  is  contained  in  a  syringe  by  which  a 
sample  of  electrolyte  may  be  drawn  from  the  cell.  To  use 
the  hydrometer  expel  the  air  from  bulb  by  pressing  it. 
Then  insert  the  nozzle  into  the  battery  opening  and  allow 
the  depressed  bulb  to  draw  sufficient  electrolyte  into  the 
syringe  to  float  the  hydrometer.  The  specific  gravity  or 
density  of  the  electrolyte  is  then  indicated  by  the  number 
on  the  hydrometer  stem  at  the  surface  of  the  electrolyte. 
Always  return  the  battery  solution  to  the  cell  from  which 
it  was  taken. 

Take  the  hydrometer  readings  just  previous  to  adding 
water.     If  the  hydrometer  readings  show  that  one  cell  is 
discharged,  or  nearly  so,  while  the  other  cells  are  charged, 
it  indicates  that  the  cell  is  defective.     This  may  be  due  to: 
1.  Short  circuits  in  that  particular  cell,  thus  discharg- 

. ,       ing  it- 

I  2.  Sulphating  of  the  plates,  caused  by  infrequent  filling 

with  water  or  by  allowing  to  stand  discharged. 

3.  Leak  in  the  cell,  thereby  requiring  more  water  than 
other  cells,  which  reduces  the  gravity. 

Freezing  of  the  electrolyte  is   avoided  by  keeping  the 
battery  fully  charged.     As  the  specific  gravity  of  the  elec- 
o* 209   trolyte  decreases  (result  of  discharging) ,  freezing  will  occur 
—Hydrome-  at  temperatures  as  follows: 
ter    syringe. 

FREEZING  POINTS  OP  ELECTROLYTE 

Specific  gravity 
1.285-1.300 
1.260 
1.210 
1.160 
1 . 120  or  lower. 

While  it  is  possible  to  freeze  a  fully  charged  battery,  it  can  be  done  only  by 
very  low  artificial  temperatures. 

If  battery  is  allowed  to  remain  discharged  or  if  plates  are  not  well 
.covered,  the  elements  become  sulphated,  and  the  capacity  is  thereby 


Condition  of  charge 

Fully  charged. 
34  discharged. 
3^3  discharged. 
%  discharged. 
Discharged. 

Freezing  point 

Can  not  freeze. 
50°  below  zero. 
20°  below  zero. 
0°  zero. 
20°-30°  above  zero. 

STARTING  AND  LIGHTING  SYSTEMS 


185 


Line  (UP  Volts  direct  Current) 


3-15  Ann 
Fuses 


Lamps 


reduced.  Sulphate  can  sometimes  be  removed  by  a  prolonged  low 
charging  rate,  but  more  frequently  the  battery  is  beyond  redemption. 
The  plates  should  always  be  well  covered  and  needless  discharge 
prevented. 

If  the  starting  motor  is  used  unnecessarily  for  cranking  the  engine  or 
for  propelling  the  car,  rapid  discharge  takes  place.  Avoid  this  whenever 
possible,  as  under  this  condition  the 
dynamo  must  be  operated  a  long 
time  to  replace  in  the  battery  the 
amount  of  current  taken  by  the  start- 
ing motor. 

If  the  battery  is  neglected  the 
center  and  upper  portions  of  plates 
become  sulphated.  This  condition  is 
not  due  to  any  fault  of  battery  ma- 
terial or  construction  nor  to  the  start- 
ing-lighting units,  but  is  directly  at- 
tributable to  inattention  and  neglect 
on  the  part  of  the  car  owner  who  has 
failed  to  add  sufficient  distilled  water 
to  the  solution  in  each  cell,  in  order  to 
keep  the  plates  properly  submerged. 
Be  sure  to  add  distilled  water  to  the 
battery  every  week  or  two. 

135.  Battery  Charging.— Figure 
210  shows  how  lamps  are  connected 
in  a  direct  current  circuit  for  battery 
charging.  Connect  a  wire  A  from 
one  side  of  lighting  source  to  one  side 
of  these  lamps,  and  to  other  side 
connect  another  wire  B.  Then  con- 
nect wire  C  to  the  other  side  of  light- 
ing source.  When  the  other  end  of 
this  third  wire  C  is  connected  to  the 
end  of  wire  B,  the  lamps  should  light. 
Now  determine  which  is  the.  positive 
(+)  and  which  is  the  negative  (  — )  wire.  Disconnect  these  two  wires  C 
and  B  which  caused  lamps  to  light,  and  dip  the  ends  in  a  bowl  of  water 
containing  a  few  tablespoonfuls  of  salt  or  one  tablespoonful  of  battery 
solution.  Hold  the  immersed  ends  about  34  in-  apart.  The  wire  from 
which  the  small  bubbles  rise  is  the  negative  ( — )  wire.  This  wire  should 
be  connected  to  the  negative  battery  post,  marked  Neg.  or  (  — ).  The 
other  wire,  which  is  positive  (+)  should  be  connected  to  the  positive 


FIG.    210. — Direct    current    charging 
method. 


186 


THE  GASOLINE  AUTOMOBILE 


battery  post  marked  Pos.  or  (+),  but  not  until  the  proper  amount  of  re- 
sistance has  been  determined. 

If  the  direct  current  is  at  110  volts  any  of  the  following  sets  of  lamps 
can  be  used  as  a  resistance  to  permit  a  current  of  4  amp.  to  flow  into  the 
battery  to  charge  it: 

8-110  volt,  16  c.p.  (50  watt)  carbon  lamps. 
4-110  volt,  32  c.p.  (100  watt)  carbon  lamps. 
16-110  volt,  25  watt  mazda  or  tungsten  lamps. 
7-110  volt,  60  watt  mazda  or  tungsten  lamps. 


FIG.  211.— The   Wagner  rectifier  charg 


ttery. 


The  charging  operation  should  continue  for  24  to  30  hours,  or  for  two 
periods  of  15  hours  each. 

If  the  voltage  or  pressure  is  220  volts,  use  sixteen  220-volt  lamps  of  16 
c.p.  each,  or  eight  lamps  of  32  c.p.  each;  and  charge  for  24  to  30  hours. 

If  only  alternating  current  is  available  the  batteries  can  be  charged  by 


STARTING  AND  LIGHTING  SYSTEMS  187 

a  rectifier  (see  Fig.  211)  which  can  be  procured  through  an  electrical  sup- 
ply house.  A  rectifier  is  an  electrical  device  for  changing  alternating  to 
direct  current.  In  ordering,  state  the  voltage  and  frequency  of  the  line 
from  which  the  charging  current  is  to  be  taken.  The  ordinary  lighting 
circuit  has  a  voltage  of  110  and  a  frequency  of  60,  but  it  is  best  to  get 
this  information  from  the  electric  light  company.  In  addition  to  this, 
the  voltage  and  capacity  of  the  battery  must  be  given.  To  charge  the 
battery  through  a  rectifier,  connect  the  rectifier  in  the  line,  as  shown  in 
Fig.  211,  following  the  directions  accompanying  the  instrument. 

136.  Wiring  Systems. — Electric  starting  systems  may  be  of  the  single 
wire  or  the  two  wire  system.     In  the  two  wire  system,  each  unit,  such  as 
lamps,  motor,  and  coil,  has  two  wires  running  to  the  battery.     In  the 
single   wire  system,   one  side  of  the 

battery  is  grounded,  that  is,  one  wire      pBBHHBHB 
is  bolted  to  the  frame  of  the  car,  and 
each  unit  has  only  a  one  wire  connec- 
tion.    In  this  method  it  is  necessary 
to  have  some  sort  of  cut-out,  so  that 
if    the    single    wire    should   become 
grounded    to    any   metallic    part,    it 
would  not  injure  the  battery.     Any 
ground   on    the    single    wire    system 
would,  of  course,  short-circuit  the  bat- 
tery.    The  cut-out  will  allow  only  a 
certain  amount  of  current  to  flow  and      i 
anything  in  excess  of  this  will  cause      FlG.  212.— Ward-Leonard  controller, 
sufficient  magnetism  in  the  core  of  the 

cut-out  to  break  the  circuit.  This  action  can  be  detected  by  a  clicking 
noise,  similar  to  the  working  of  a  telegraph  instrument. 

There  are  a  large  number  of  starting  and  lighting  systems  on  the 
market,  the  details  of  which  we  will  now  take  up.  The  most  important 
technical  features  to  study  are  the  different  methods  of  controlling  the 
output  of  the  dynamo. 

137.  The  Ward-Leonard  System. — The  Ward-Leonard  constant  cur- 
rent type  of  controller  is  shown  in  Fig.  212  and  operates  as  follows: 
The  proper  charging  of  the  battery  is  automatically  regulated  by  the 
controller.     When  the  car  speed  becomes  approximately  7  miles  per  hour, 
the  dynamo  armature  will  give  a  voltage  sufficient  to  charge  the  batteries. 
The  circuit  between  the  dynamo  and  the  batteries  is  normally  open,  but 
when  the  voltage  of  the  dynamo  becomes  proper  for  charging,  the  coil 
A  on  the  magnet  core  B  magnetizes  the  core  sufficiently  to  attract  the  arm 
C.     This  arm  moves  toward  the  core  B,  and  thus  two  spark-proof 
points    D   and   D'   are   brought   together,  establishing  the  circuit  be- 


188 


THE  GASOLINE  AUTOMOBILE 


tween  the  battery  and  the  dynamo,  and  the  dynamo  begins  to  charge 
the  batteries. 

Unless  some  method  of  controlling  it  is  adopted,  the  dynamo  voltage 
increases  with  the  speed.  The  dynamo  should  charge  at  about  7  miles 
per  hour,  but  when  the  car  runs  at  a  much  higher  .speed,  as  15  to  60 
miles  per  hour,  it  is  desirable  that  the  dynamo  voltage  shall  not  increase. 
If  allowed  to  increase,  such  an  excessive  dynamo  voltage  would 
tend  to  cause  sparking  at  the  brushes,  excess  current  and  consequent 
trouble  at  the  commutator,  and  excessive  wear  and  heating  of  the  bear- 


FIG.  213. — Ward-Leonard  wiring  diagram. 

ings.  It  would  also  cause  an  excessive  amount  of  current  to  flow  through 
the  battery.  To  prevent  this,  the  strength  of  the  dynamo  field,  and  con- 
sequently the  output  of  the  dynamo,  is  made  dependent  on  the  touching 
of  the  two  points  E  and  E'.  The  coil  F  on  the  magnet  core  G  carries 
the  armature  current,  and  if  this  current  becomes  a  certain  amount 
(usually  in  practice  10  amp.)  the  core  becomes  sufficiently  magnetized  to 
attract  the  finger  H.  This  separates  the  contacts  E  and  E',  and  a  re- 
sistance M  is  inserted  in  the  field  circuit.  This  weakens  the  fields  and 
causes  the  amperes  to  decrease.  When  the  current  decreases  to  a  pre- 
determined amount  (say  9  amp.),  the  coil  F  does  not  magnetize  the  core 
Cr  enough  to  overcome  the  pull  of  the  spring  J.  The  spring  pulls  together 


STARTING  AND  LIGHTING  SYSTEMS 


189 


the  points  E  and  E';  the  full  field  strength  is  restored  and  the  current 
tends  to  increase.  Under  operating  conditions  the  finger  H  automatically 
and  rapidly  vibrates  at  such  a  rate  as  to  keep  the  current  constant. 
As  a  result,  the  dynamo  will  never  charge  above  a  predetermined  amount 
(10  amp.)  no  matter  how  high  the  speed  of  the  car,  but  will  produce  a 
substantially  constant  current. 

In  case  the  engine  speed  becomes  so  low  that  the  dynamo  volts  are 
less  than  those  of  the  battery,  the  magnetism  caused  by  the  coil  A, 
Fig.  212,  is  weakened  so  that  the  spring  K  pulls  the  contacts  D  and  Df 
apart.  Thus,  the  circuit  between  the  dynamo  and  battery  is  opened 


FIG.  214. — Installation  of  Ward-Leonard  system. 

when  the  dynamo  speed  is  too  low  for  proper  charging.  An  auxiliary 
series  coil  L  on  core  B  acts  to  insure  the  perfect  demagnetization  of  the 
core  on  reversal  of  current. 

The  technical  internal  wiring  diagram,  in  Fig.  213,  shows  the  con- 
nections of  the  dynamo,  the  battery  and  the  controller.  Figure  214 
shows  a  typical  installation  and  wiring  layout  for  the  complete  two-unit 
starting  and  lighting  system.  The  connections  of  the  motor  are  very 
simple.  There  are  two  wires  from  the  battery  to  the  motor,  with  a 
switch  operated  by  the  foot  pedal.  This  pedal  also  shifts  the  starting 
gears  into  mesh  with  the  teeth  on  the  flywheel.  When  the  engine  starts, 
the  foot  pedal  is  released,  the  gears  are  disengaged,  the  switch  opened 


190 


THE  GASOLINE  AUTOMOBILE 


and  the  motor  becomes  inoperative  until  it  is  wanted  to  start  the  engine 
again. 

138.  The  Delco  System. — A  single-unit  motor-generator  is  used  in  this 
system.  This  unit  also  carries,  mounted  on  it,  the  ignition  system.  A 
general  view  of  a  Delco  system  is  shown  in  Fig.  215.  The  motor-generator 
has  separate  sets  of  brushes,  commutator,  and  windings — one  used  when 
serving  as  a  motor  and  one  when  acting  as  a  generator.  It  also  has  two 
driving  connections.  When  acting  as  a  generator,  it  is  usually  driven 
from  the  pump  shaft  by  a  clutch  connection  as  shown  at  the  right  in  Fig. 
216,  which  shows  the  motor-generator  as  used  on  the  1915  Buick  cars. 
When  the  starting  pedal  is  operated,  this  clutch  is  disconnected,  the  gear 


FIG.  215. — Delco  starting  and  lighting  system. 

connection  is  made  from  the  motor  pinion  to  the  flywheel,  the  brushes  are 
removed  from  the  generator  commutator  and  the  motor  brushes  put  into 
contact  with  the  motor  commutator.  When  the  pedal  is  released,  the 
connections  are  made  to  operate  as  a  generator. 

Voltage  Regulator. — The  Delco  system  of  current  regulation  uses  a 
resistance  coil  immersed  in  a  tube  of  mercury,  as  shown  in  Fig.  217. 
This  instrument  serves  to  control  the  amount  of  current  flowing  from  the 
generator  to  the  storage  battery.  By  referring  to  Fig.  217  the  construc- 
tion and  operation  of  this  device  will  be  made  clear.  A  magnet  coil  A 
surrounds  the  upper  half  of  the  mercury  tube  B.  Within  this  mercury 
tube  is  a  plunger  C,  comprising  an  iron  tube  with  a  coil  of  resistance  wire 


STARTING  AND  LIGHTING  SYSTEMS 


191 


wrapped  around  the  lower  portion  on  top  of  a  special  insulation.  One 
end  of  this  resistance  wire  is  connected  to  the  lower  end  of  the  tube,  the 
other  end  being  connected  to  a  needle  D  carried  in  the  center  of  the 
plunger.  The  lower  portion  of  the  mercury  tube  is  divided  by  an 
insulating  tube  into  two  concentric  wells,  the  plunger  tube  being  partly 
immersed  in  the  outer  well,  and  the  needle  in  the  inner  well.  The  space 
in  the  mercury  tube  above  the  body  of  mercury  is  filled  with  an  especially 
treated  oil  which  serves  to  protect  the'  mercury  from  oxidization,  to 
lubricate  the  plunger,  and  to  form  a  dash  pot  for  the  plunger.  Inasmuch 
as  the  voltage  of  the  storage  battery  varies  with  its  condition  of  charge,  the 
intensity  of  the  magnetic  pull  exerted  by  the  magnet  coil  A  upon  the 


STARTING 
/PEDAL 


\W    fnll 

FIG.  216. — Delco  motor-generator. 


nSTRBUTOR  SHATT 
SPRAL    GEAR 


plunger  C  varies,  and  causes  the  plunger  to  move  in  and  out  of  the  mercury 
as  the  voltage  changes.  When  the  battery  is  in  a  discharged  condition, 
the  plunger  C  assumes  a  low  position  in  the  mercury  tube.  When  the 
plunger  is  at  a  low  position,  the  coil  of  resistance  wire  carried  upon  its 
lower  portion  is  immersed  in  the  mercury,  and  as  the  plunger  rises  the  coil 
is  withdrawn.  Now  the  current  to  the  shunt  field  of  the  generator  must 
follow  a  path  leading  to  the  outer  well  of  mercury,  through  the  resistance 
coil  wound  on  the  plunger  tube,  to  the  needle  carried  at  the  center  of  the 
plunger,  into  the  center  well  of  mercury  and  out  of  the  regulator. 

It  will  be  seen  that,  as  the  plunger  is  withdrawn  from  the  mercury, 
more  resistance  is  thrown  into  this  circuit,  due  to  the  fact  that  the  current 
must  pass  through  a  greater  length  of  resistance  wire.  This  greater 
resistance  in  the  field  of  the  generator  causes  the  amount  of  current  flow- 
ing to  the  battery  to  be  gradually  reduced  as  the  battery  nears  a  state 
of  complete  charge,  until  finally  the  plunger  is  almost  completely  with- 
drawn from  the  mercury,  throwing  the  entire  length  of  resistance  coil  into 
the  shunt  field  circuit,  thus  causing  a  condition  of  practical  electric 


192 


THE  GASOLINE  AUTOMOBILE 


balance  between  the  battery  and  generator,  and  obviating  any  possi- 
bility of  overcharging  the  battery. 

Automatic  Cut-out  Relay. — The  automatic  cut-out,  Fig.  218,  is  located 
between  the  voltage  regulator  and  ignition  relay,  in  the  apparatus  box. 
This  instrument  closes  the  circuit  between  the  generator  and  the  storage 
battery  when  the  generator  voltage  is  high  enough  to  charge  the  storage 
battery.  It  also  opens  the  circuit  as  the  generator  slows  down  and  its 
voltage  becomes  less  than  that  of  the  storage  battery,  thus  preventing  the 
battery  from  discharging  back  through  the  generator.  The  cut-out 


FIG.  217. — Delco  voltage  regulator.          FIG.  218. — Delco  cut-out  relay. 

relay  is  an  electro-magnet  with  a  compound  winding.  The  voltage  coil, 
or  fine  wire  winding,  is  connected  directly  across  the  terminals  of  the 
generator.  The  current  coil,  or  coarse  wire  winding,  is  in  series  with  the 
circuit  between  the  generator  and  the  storage  battery,  and  the  circuit  is 
opened  and  closed  at  the  contacts  A. 

When  the  engine  is  started,  the  generator  voltage  builds  up  and  when 
it  reaches  about  6  volts  the  current  passing  through  the  voltage  winding 
produces  enough  magnetism  to  overcome  the  tension  of  the  spring  B, 
attracting  the  magnet  armature  C  to  core  D,  which  closes  the  contacts  A. 
These  contacts  close  the  circuit  between  the  generator  and  storage  battery. 


STARTING  AND  LIGHTING  SYSTEMS 


193 


The  current  flowing  through  the  coarse  wire  winding  increases  the  pull  on 
the  armature  and  gives  a  good  contact  of  low  resistance  at  the  points  of 
contact. 

•  When  the  generator  slows  down  and  its  voltage  drops  below  that  of 
the  storage  battery,  the  battery  sends  a  reverse  current  through  the  coarse 
wire  winding,  which  kills  the  pull  on  the  magnet  armature  C.  The  spring 
B  then  opens  the  circuit  between  the  generator  and  battery,  and  will  hold 
it  open  until  the  generator  is  again  started  up. 

139.  Gray  and  Davis  Starting  and  Lighting  System.— The  Gray  and 
Davis  starting  and  lighting  system  consists  of  a  6^  volt  shunt  wound 
generator  for  charging  the  battery  and  furnishing  current  for  the  lights, 
and  a  series  wound  motor  for  cranking  the  engine. 


COMMUTATOR 


FIELD  COIL 
f 

ARMATURE 


FIG.  219. — Gray  and  Davis  generator. 

The  generator  or  dynamo  is  shown  in  Fig.  219.  This  generator  has 
two  shunt  field  windings,  so  arranged  that  the  field  strength  or  magnetism 
automatically  increases  as  additional  load  comes  on.  The  technical 
wiring  diagram  for  the  whole  starting  and  lighting  system  is  shown  in 
Fig.  220. 

Regulator  Cut-out. — The  regulator  cut-out,  shown  in  Fig.  221,  per- 
forms two  duties:  first,  to  regulate  the  dynamo  for  uniform  output;  sec- 
ond, to  connect  the  dynamo  into  the  system  only  when  sufficient  current  is 
generated  to  charge  the  battery  and  to  disconnect  the  dynamo  from  the 
battery  when  the  dynamo  slows  down  so  that  the  current  is  insufficient 
to  charge  the  battery,  and  thus  prevent  the  battery  from  discharging 
through  the  dynamo. 

When  the  dynamo  is  at  rest,  the  cut-out  points  are  open  and  the 


194 


THE  GASOLINE  AUTOMOBILE 


FIG.  220. — Technical   wiring   diagram    with   grounded   switch — Gray    and    Davis 
starting  and  lighting  system. 


STARTING  AND  LIGHTING  SYSTEMS 


195 


regulator  points  remain  closed.  As  the  dynamo  first  speeds  up,  the  regu- 
lator points  remain  closed.  Thus,  the  field  resistance  is  cut  out,  permit- 
ting the  dynamo  to  build  up  under  full  field  strength.  When  the  proper 
voltage  is  reached,  the  cut-out  points  close,  permitting  current  to  flow 
through  the  series  winding  to  the  system. 

As  the  dynamo  speed  increases  beyond  that  necessary  for  full  output, 
the  pull  of  the  shunt  winding  attracts  the  regulator  armatures.  This  re- 
duces the  pressure  at  the  regulator  points  and  inserts  a  resistance  into 
the  field  circuit,  which  prevents  further  increase  of  output.  The  vary- 
ing of  the  pressure  at  the  points,  which  allows  the  resistance  to  be  put 
into  the  circuit,  is  intermittent.  The  frequency  is  in  proportion  to  the 
speed  variation. 


SHIFTER   PORK  JPRING- 

smrTER  roRK 

STOP  COLLAR 
SWITCH  ROD  - 


FIG.  221. — Gray  and  Davis  regulator 
cut-out  mounted  on  dynamo. 


FIG.  222. — Gray   and   Davis   starting 
motor   and   connections. 


The  dynamo  terminals  are  marked  B  and  L.  B  is  negative  (  — ). 
It  is  the  end  of  the  regulator  cut-out  series  winding,  and  connects  to  the 
battery  through  the  indicator.  L  is  also  negative  (  — ).  It  is  con- 
nected to  the  series  winding  at  a  given  distance  from  the  end  and  con- 
nects to  the  lamps  through  the  lighting  switch.  The  positive  brush- 
holder  of  the  dynamo  connects  or  " grounds"  to  the  dynamo  frame. 
Therefore,  the  dynamo  frame  is  positive  (+).  Connections  between  the 
dynamo  and  the  regulator  are  as  follows: 

The  three  terminals  at  the  end  of  the  regulator  cut-out  opposite  the 
terminals  marked  B  and  L  connect  to  the  dynamo  windings,  as  shown  in 
the  wiring  diagram. 

A  connects  to  dynamo  negative  (  — )  brush. 

FI  connects  to  the  one  field  coil. 

F  connects  to  the  other  field  coil. 

The  starting  motor  and  its  connections  are  shown  in  Fig.  222.     The 

starting  motor  cranks  the  engine  until  it  runs  under  its  own  power.     It 
21 


196 


THE  GASOLINE  AUTOMOBILE 


is  the  link  between  battery  and  engine.  It  converts  electrical  into 
mechanical  energy.  Electrically  it  is  connected  to  the  battery  through 
heavy  cables  and  the  starting  switch.  Mechanically  it  is  connected  to 
the  engine  through  a  gear  reduction  having  a  sliding  flywheel-engaging 
pinion  and  an  over-running  clutch. 

The  sliding  engaging  pinion  and  the  starting  switch  are  operated 
by  the  same  operation  of  the  starting  pedal,  so  that  electrical  and  me- 
chanical connection  and  disconnections  occur  at  the  same  time. 

When  the  starting  switch  is  closed,  the  electrical  energy  stored  in  the 
battery  is  instantly  transmitted  to  the  motor,  causing  the  armature  to 
rotate.  This  mechanical  energy  is  transmitted  through  the  gears  and 
over-running  clutch  to  the  engine,  causing  it  to  rotate. 

When  the  starting  pedal  is  pressed  to  the  full  limit  of  its  travel,  it 
moves  the  switch  rod  in  the  direction  of  the  arrow  in  Fig.  222.  This 

moves  the  sliding  pinion  forward  and 
closes  the  starting  switch.  If  the 
sliding  pinion  is  in  a  meshing  posi- 
tion, it  slides  into  mesh  with  the  fly- 
wheel gear;  but  if  the  pinion  teeth, 
instead  of  sliding  between,  should 
strike  the  ends  of  the  flywheel  teeth, 
the  switch  rod  completes  its  travel, 
which  compresses  the  shifter  fork 
spring  and  closes  the  switch.  When 
the  pinion  begins  to  turn,  the  com- 
pressed spring  throws  the  sliding 
pinion  into  full  engagement  with  the 
flywheel  gear  and  permits  the  start- 
ing motor  to  crank  the  engine. 
When  the  engine  picks  up,  the  roll 
clutch  prevents  the  engine  from  driving  the  starting  motor,  as  the  gears 
are  in  mesh  until  the  starting  pedal  is  released. 

Over-running  Clutch. — The  purpose  of  the  over-running  clutch  is  to 
permit  the  engine,  when  cranked  by  the  starting  motor,  to  pick  up  with- 
out speeding  up  the  starting  motor,  which  is  temporarily  connected  to  the 
engine  while  the  starting  pedal  is  pressed.  This  over-running  clutch 
is  merely  a  roller  ratchet  connection  between  one  of  the  gears  and  its 
shaft.  This  is  shown  on  Fig.  222  and  is  shown  more  in  detail  in  Fig. 
223.  The  gears  1  and  2  are  shown  in  the  reversed  position  in  Fig.  223 
from  that  which  they  occupy  in  Fig.  222. 

When  the  starting  motor  pinion  No.  1  of  Fig.  223  is  rotated  in  a 
counter-clockwise  direction,  the  intermediate  gear  No.  2  rotates  clock- 
wise; the  rolls  No.  3  are  thus  rolled  into  the  wedge  angles  between  the 


FIG.  223. — Gray  and  Davis  over-run- 
ning clutch. 


STARTING  AND  LIGHTING  SYSTEMS 


197 


curved  surface  of  the  clutch  center  No.  4  and  the  inner  surface  of  the 
intermediate  gear  No.  2,  with  increased  pressure  until  the  friction  is 
sufficient  to  drive  intermediate  shaft  No.  5,  which  is  keyed  to  clutch 
center  4. 

Springs  No.  21,  back  of  the  plungers  No.  22,  keep  rolls  No.  3  firmly 
within  wedge  angles  so  that  they  grip  as  soon  as  the  starting  motor 
turns.  When  the  engine  runs  faster  than  when  rotated  by  the  starting 
motor,  the  rolls  are  released  from  the  wedge  angles,  and  the  clutch  center 
4  can  run  ahead  without  carrying  the  gear  2  with  it. 

140.  Wagner  Starting  and  Lighting  System. — The  two-unit  Wagner 
system  consists  of  the  charging  generator,  Fig.  224,  the  starting  motor, 
Fig.  225,  and  the  generator  relay,  Fig.  226.  The  wiring  may  be  either 
the  two  wire  or  single  wire  system  at  the  option  of  the  manufacturer. 


FIG.  224. — Wagner  generator. 

The  method  of  connecting  the  generator  to  the  engine  may  be  by  a 
silent  chain  or  by  spur  or  spiral  gears.  The  starter  motor  may  be  con- 
nected to  the  engine  shaft  by  chain  and  over-running  clutch,  or  by  pin- 
ion meshing  with  the  flywheel  and  operated  by  the  Eclipse  Bendix  system, 
similar  to  the  Westinghouse  clutch  shown  in  Fig.  229.  The  starting 
motor  turns  the  engine  over  at  about  100  r.p.m.,  which  is  fast  enough  to 
start  on  most  magnetos. 

In  Fig.  224,  E  is  the  commutator  and  F,  G,  H,  and  /  are  the  brushes. 
The  brushes  H  and  I  collect  the  current  from  the  commutator  and  fur- 
nish this  current  for  charging  the  battery  through  the  relay.  The  brushes 
F  and  G  collect  from  the  commutator  the  current  used  for  exciting  the 
fields. 

The  function  of  the  relay,  Fig.  226,  is  to  connect  the  battery  to  the 
generator  when  the  voltage  of  the  generator  is  slightly  above  the  voltage 


198 


THE  GASOLINE  AUTOMOBILE 


of  the  battery.  It  also  disconnects  the  generator  from  the  battery  when 
the  voltage  of  the  generator  falls  below  the  voltage  of  the  battery.  This 
relay  consists  of  two  magnet  coils,  L  and  M ,  wound  on  an  iron  core  N. 
This  iron  core  attracts  and  repels  an  iron  lever  0.  At  the  end  of  this  lever 
0  are  two  main  contact  points  P  and  Q  at  which  the  contact  between  the 
generator  and  battery  is  made  and  broken.  There  are  also  supplied  two 
auxiliary  contact  points  R  and  S  which  are  for  the  purpose  of  minimizing 
the  sparking  at  the  main  contact  points  P  and  Q.  The  coil  M,  called  the 
shunt  coil,  is  connected  directly  across  the  two  brushes  H  and  /,  Fig.  224, 
and  therefore  the  full  generator  voltage  is  impressed  across  the  ends  of  this 
coil.  The  coil  L,  called  the  series  coil,  is  connected  in  series  with  the 


FIG.  225. — Wagner  starting  motor. 

battery  and  generator  and  therefore  this  coil  carries  the  charging  current 
when  the  battery  is  being  charged. 

The  action  of  the  relay  is  as  follows:  When  the  engine  is  started,  the 
generator  is  driven  by  the  engine,  and  it,  therefore,  increases  and  de- 
creases in  speed  with  the  engine.  When  the  engine  is  speeded  up,  the 
generator  follows  with  corresponding  increase  in  speed  and  the  voltage 
of  the  generator  rises  as  the  speed  increases.  As  soon  as  the  generator 
voltage  gets  to  a  point  above  the  voltage  of  the  battery,  which  is  ap- 
proximately 6  volts,  the  coil  M ,  Fig.  226,  pulls  the  iron  lever  0  toward  the 
magnet  core,  thereby  closing  the  contact  at  the  points  P-Q  and  R-S. 
As  soon  as  this  contact  is  made,  the  generator  is  connected  to  the  battery, 
and  a  charging  current  will  flow  from  the  generator  to  the  battery  through 
the  series  coil  L,  which  is  in  series  with  the  generator  and  battery.  The 
generator  continues  to  charge  as  long  as  these  contact  points  P-Q  and  R-S 
remain  together,  but  when  the  engine  speed  is  decreased,  so  that  the 
generator  voltage  falls  below  the  battery  voltage,  the  battery  will  dis- 


STARTING  AND  LIGHTING  SYSTEMS  199 

charge  through  the  generator  and  therefore  through  the  coil  L.  This 
discharge  current,  being  in  the  opposite  direction  from  the  charging  current 
will  neutralize  the  effect  of  coil  M  and  allow  the  spring  T  to  pull  the  lever 
0  away  from  the  magnet  core,  thereby  opening  the  contact  at  the  points 
P-Q  and  R-S.  As  soon  as  these  contacts  open,  the  battery  is  "  off  charge." 
The  engine  speed  at  which  this  relay  closes  corresponds  to  a  car  speed  of  7 
to  10  miles  per  hour. 

Studebaker  automobiles  use  the  Wagner  system  and  are  equipped 
with  an  instrument  called  a  Battery  Indicator  or  Tell-tale.  This  instru- 
ment is  installed  on  the  dashboard  of  the  car  and  is  connected  in  the 
battery  circuit.  The  tell-tale  gives  indication  of  battery  current,  showing 


M     L 


FIGURES 

RS  PQ  N    O 

FIG.  226. — Wagner  relay. 

off  when  no  current  is  being  taken  from,  or  being  put  into,  the  battery; 
discharge  when  current  is  being  taken  out  of  the  battery  by  lights,  ignition, 
or  horn;  and  showing  charge  when  the  generator  is  charging  the  battery. 
141.  The  Westinghouse  Single-unit  System. — The  Westinghouse 
electric  starter-lighter  equipment  consists  of  a  motor-generator.  In  the 
motor-generator  the  functions  of  both  starting  and  lighting  are  combined 
in  one  machine.  A  12-volt  system  is  used.  The  motor-generator  is 
permanently  geared  or  chain-connected  to  the  engine.  When  the  circuit 
is  closed  by  the  starting  switch,  the  motor  windings  take  current  from 
the  battery  and  drive  the  engine  until  firing  takes  place.  The  motor- 
generator  is  then  driven  by  the  engine,  and,  as  speed  increases,  it  soon 


200 


THE  GASOLINE  AUTOMOBILE 


generates  battery  voltage.  At  all  higher  speeds  it  charges  the  battery  and 
furnishes  the  current  for  the  lights. 

There  is  an  emergency  feature  on  the  Hupmobile  that  prevents  stalling 
of  the  engine.  At  low  speeds  the  motor-generator  acts  as  a  motor  and 
assists  the  engine,  causing  an  immediate  restart  in  case  of  stalling. 

It  should  be  remembered  that  at  speeds  of  less  than  9  miles  per  hour, 
with  engine  on  high  gear  the  motor-generator  acts  as  a  motor,  assists 
in  propelling  the  car,  and  therefore  takes  current  from  the  battery;  and 
if  such  running  is  indulged  in  to  any  extent  the  battery  will  become 
exhausted.  Also,  allowing  the  engine  to  idle  at  low  speeds  will  discharge 
the  battery.  A  little  care  in  avoiding  low  speeds  and  engine  idling  will 


FIG.  227.— Westinghouse  Ford  outfit. 

prevent  this.  Figure  227  shows  the  Westinghouse  single-unit  system  for 
Ford  cars,  while  the  wiring  diagram  is  given  in  Fig.  228. 

142.  Westinghouse  Two-unit  System. — 'The  starting  motor  for  the 
Westinghouse  two-unit  system  is  shown  in  detail  in  Fig.  229.  It  may 
be  equipped  with  either  a  non-automatic  or  an  automatic  pinion-shift, 
flywheel  drive. 

Figure  230  shows  the  mechanical  and  electrical  connections  of  motor 
and  switch  for  non-automatic  pinion-shift,  flywheel  drive.  At  A  is 
shown  the  "off"  position  of  the  shift  pinion  and  switch  contactor. 
Pressure  on  the  starting  lever  moves  the  shift  rod  first  to  the  position 
shown  in  B,  closing  the  motor  circuit  at  P  and  P'  through  the  resistance 
R;  this  starts  the  motor  at  low  speed.  Further  motion  of  the  shift  rod  to 
position  C  opens  the  electric  circuit  but  the  motor  and  pinion  continue 


STARTING  AND  LIGHTING  SYSTEMS 


201 


to  turn,  owing  to  their  momentum.  When  position  C  is  reached,  the 
pinion  is  still  turning  slowly,  so  that  it  can  not  fail  to  mesh  with  the  gear, 
but  as  power  is  turned  off  the  motor,  there  is  no  difficulty  in  sliding  the 
teeth  into  full  engagement.  As  soon  as  the  teeth  do  engage,  further  foot 
pressure  on  the  starting  lever  shifts  the  rod  to  position  shown  in  D, 
closing  the  electric  circuit  at  Q  after  the  pinion  and  gear  have  meshed  a 
sufficient  distance  to  present  a  good  bearing  length  on  the  teeth;  this 


Head  Lights- 


7-1 

Tail  Light 

FIG.  228. — Wiring  diagram  for   Westinghouse   Ford  outfit. 

connects  the  motor  directly  to  the  storage  battery  so  that  full  power  is 
impressed,  and  it  turns  the  engine  over  until  the  starting  lever  is  released 
or  the  engine  picks  up  on  its  own  power.  There  is  an  over-running  clutch 
between  the  flywheel  pinion  and  the  motor,  so  that,  if  the  pedal  is  not 
promptly  released  when  the  engine  picks  up,  the  motor  is  not  driven  by  the 
engine. 


202 


THE  GASOLINE  A  UTOMOBILE 


L 


ARMATURE    COMMUTATOR . ':".   ^   ...  . 

FIG.  229. — Westinghouse  starting  motor  disassembled. 


FIG.  230.— Connections     of    Westinghouse     starting     motor     with     non-automatic 
pinion  shift. 


STARTING  AND  LIGHTING  SYSTEMS 


203 


In  the  Eclipse-Bendix  pinion-shift,  as  shown  in  Fig.  231,  the  starter 
motor  is  fitted  with  a  special  threaded  shaft  which  automatically  shifts 
the  pinion  into  mesh  with  the  flywheel  when  the  starting  switch  is  closed. 
When  the  switch  is  closed,  the  full  battery  voltage  is  impressed  on  the 
motor,  and  it  starts  immediately.  The  pinion,  when  the  motor  is  at  rest, 
is  within  the  screwshaft  housing  and  entirely  away  from  the  flywheel 
gear.  The  threaded  shaft  is  connected  to  the  reduction  gear  shaft  by  a 
spring  which  thus  forms  a  flexible  coupling.  As  the  load  is  not  large 
enough  to  compress  the  spring  when  the  motor  starts,  the  threaded  shaft 
is  immediately  revolved  by  the  spring  in  released  position.  The  pinion 
moves  out  on  its  shaft  by  virtue  of  the  revolving  threads,  until  it  reaches 
the  flywheel.  If  the  teeth  of  the  pinion  and  flywheel  meet  instead  of 

tortmg  Motor 

[lectn-Magnetic 
Starting  Switch  r 


'orting  Motor 


A,    With    hand    or    foot 
operated  starting  switch. 


B,  With  electro-magnetic  starting  switch 
controlled  by  push  button. 


FIG.  231.  —  Connections 


of    Westinghouse    starting 
pinion  shift. 


motor    with    Eclipse-Bendix 


meshing,  the  spring  allows  the  pinion  to  revolve  until  it  meshes  with  the 
flywheel.  When  the  pinion  is  fully  meshed  into  the  flywheel  teeth,  the 
spring  compresses,  and  the  pinion  is  then  revolved  by  the  motor  as 
through  a  continuous  shaft,  turning  the  engine  over.  When  the  engine 
fires  and  the  peripheral  speed  of  the  flywheel  continuously  exceeds  that 
of  the  driving  pinion,  it  forces  the  latter  out  of  mesh,  and  it  is  returned  to 
its  original  position  in  the  screwshaft  housing. 

The  Westinghouse  lighting  and  starting  generator,  as  shown  in  detail 
in  Fig.  232,  is  operated  by  belt,  chain,  or  gear  drive  from  the  engine  and 
furnishes  current  to  the  storage  battery  and  lights.  While  the  engine  is 
stopped  or  running  at  very  low  speed,  the  lights  are  supplied  entirely  by 
the  battery.  A  magnetic  switch  in  the  generator  automatically  con- 
nects the  generator  to  the  lighting  system  and  battery  when  the  engine  is 
running  at  approximately  8  miles  per  hour  car  speed  on.  direct  drive. 
When  running  on  the  gears,the  switch  closes  at  a  much  lower  car  speed. 
If  no  lights  are  then  in  use,  the  battery  begins  to  be  charged  when  this 
switch  makes  the  electrical  connection.  If  the  lights  are  burning,  the 


204 


THE  GASOLINE  AUTOMOBILE 


generator  furnishes  part  of  the  current  to  them;  as  the  speed  increases,  the 
proportion  of  current  supplied  by  the  generator  increases,  until  at  high 
speed  the  generator  supplies  all  of  the  current  to  the  lights  and  in  addition 
charges  the  battery.  The  amount  of  current  the  generator  furnishes  to 
the  battery  depends  upon  the  number  of  lamps  burning  and  upon  the 
speed  of  the  engine. 

143.  The  U.  S.  L.  Electric  Starting  and  Lighting  System.—  This  is  a 
unique  system  in  which  a  single  unit  motor-generator  is  connected  directly 
to  the  engine  shaft,  taking  the  place  of  the  flywheel. 

The  motor-generator  consists  of  a  stationary  housing,  a  set  of  fields 
complete  with  poles  and  coils,  an  aluminum  case,  and  a  dust  ring,  as 


CO 

•-•  . 

BRUSHE! 

FIG.  232. — Westinghouse  starting  and  lighting  generator  disassembled. 

shown  in  detail  in  Fig.  233.  The  armature  replaces  the  flywheel  of  the 
engine,  being  attached  to  the  crank  shaft  in  its  stead  as  shown  in  Fig.  234. 
When  the  starting  button  is  pressed  down,  the  current  from  the  battery- 
starts  the  electric  motor.  This  revolves  the  crank  shaft  of  the  engine. 
With  the  switch  of  the  ignition  coil  in  battery  position,  the  explosions  will 
commence.  The  starting  button  should  be  quickly  released,  thus  auto- 
matically changing  the  electric  motor  into  an  electric  generator.  As  the 
speed  of  the  engine  increases,  the  generator  gradually  commences  charging 
the  battery,  restoring  the  current  discharged  during  the  starting  operation. 
Regulator. — The  regulator  is  located  on  the  dash  under  the  cowl  and 
instrument  board.  It  performs  four  principal  functions:  1,  closes  the 
switch  when  the  generator  voltage  is  sufficient  to  charge  the  battery; 
2,  opens  the  switch  when  the  generator  voltage  is  insufficient  and  the 


STARTING  AND  LIGHTING  SYSTEMS  205 

current  reverses;  3,  regulates  the  maximum  charge  to  the  battery;  and  4 
controls  the  generator  voltage  on  open  battery  circuit. 

An  indicating  arrow  is  visible  through  the  window  in  the  regulator 
cover  when  the  switch  is  closed  and  the  storage  battery  is  being  charged. 
It  disappears  when  the  contact  is  broken.  The  switch  should  close  when  a 
car  speed  of  10  to  12  miles  per  hour  is  attained,  and  open  when  the  speed 
falls  below  about  the  same  rate,  or  when  the  motor  stops  altogether. 

The  regulator  consists  of  a  magnet  coil  which  pulls  the  switch  lever 
into  contact  when  the  proper  car  speed  is  attained.  It  also  acts  on  a 
carbon  pile  lever  and  controls  the  field  current  by  increasing  or  decreasing 
the  resistance  through  the  carbon  discs  at  the  top  of  the  regulator. 


CASE  &  FIELDS  RATCHET  SPRING 


Fia.  233.— Details  of  U.  S.  L.  system. 

If  the  engine  does  not  turn  over  when  you  first  press  on  the  button, 
immediately  let  up  the  button  and  try  again  several  times  quickly.  Do 
not  hold  your  foot  on  it  long,  as  this  will  needlessly  drain  the  current  from 
the  battery. 

If  the  motor  fails  to  respond  when  the  starter  button  is  pressed 
several  times  quickly,  the  battery  is  too  low.  In  such  cases,  do  not  continue 
to  hold  the  starting  button  down ;  release  it,  and  crank  the  motor  by  hand, 
running  it  at  a  charging  rate  of  10  to  15  amp.  giving  the  generator  an 
opportunity  to  recharge  the  battery.  If  you  repeatedly  press  the  starting 
button  without  running  the  engine,  it  will  only  be  a  question  of  time  before 
the  battery  will  be  exhausted. 

144.  Jesco  Single -unit  Electric  Starter  and  Lighter. — The  complete 
system  consists  of  a  starter-generator,  with  controller  and  starting  switch 


206  THE  GASOLINE  AUTOMOBILE 

mounted  thereon,  in  connection  with  a  6  volt,  100  amp.-hour  storage 
battery,  switch,  and  wiring  for  lights.  The  starter-generator  is  connected 
either  by  coupling,  by  silent  chain,  or  by  gears  to  the  crank  shaft  of  the 
engine,  at  a  ratio  of  either  one  to  one,  or  two  to  one. 

The  electric  machine  performs  as  a  series  motor  at  time  of  starting 
and  as  a  shunt  generator  for  storing  current  in  the  battery  and  supplying 
the  lights.  As  a  starter,  a  gear  reduction  is  automatically  engaged,  and 


CLUTCH  BEARING  GREASE  CU 


CRANK  SHAFT 
LOCKING  NUT 

CRANK  SHAFT  EXTENSION  BOL 
BALL  THRUST  WASHER 

BALL  THRUST 
CLUTCH  FLANGE  NUT 
CLUTCH  SPRING  THRUST  WASHER 

CLUTCH  SPRING 
CLUTCH  CONE  BUSHING 

CLUTCH  CONE 

CLUTCH  LEATHE 


FIG.  234. — Section  of  U.  S.  L.  motor-generator. 

after  the  engine  starts,  this  transmission  locks  by  action  of  a  multiple  disc 
clutch,  and  no  gears  are  in  operation.  This  works  automatically  and 
requires  little  attention,  outside  of  oiling.  The  electrical  regulating  mech- 
anism is  contained  in  the  little  box  on  top  of  the  starter-generator. 
The  regulation  is  taken  care  of  by  a  differential  shunt  field  in  connection 
with  an  automatic  regulator. 

Charging  begins  at  approximately  8  miles  an  hour  car  speed.  At  15 
miles  an  hour  the  maximum  charging  rate  is  reached  and,  by  regulation, 
remains  constant  through  all  speeds  in  excess  of  that  amount.  The 


STARTING  AND  LIGHTING  SYSTEMS  207 

battery  cut-out  automatically  disconnects  the  battery  when  the  generator 
is  not  charging,  preventing  a  back  flow  from  battery  to  machine. 

The  wiring  is  extremely  simple,  having  only  two  leads  from  starter- 
generator  to  battery,  with  the  lighting  of  car  and  the  indicating  meters 
arranged  as  desired.  The  Jesco  system  as  used  on  a  Continental  six 
engine  is  shown  in  Fig.  235. 

145.  Care  of  Starting  and  Lighting  Apparatus. — A  periodical  in- 
spection should  be  made  of  wiring,  insulation  and  all  connections.  Wir- 
ing and  connections  should  be  protected  against  grease,  oil,  and  me- 
chanical injury. 


FIG.  235. — Jesco  starting  installation. 

Use  the  same  consideration  for  your  auto  lighting  system  that  you 
do  for  electric  light  in  your  house.  Do  not  leave  your  car  all  night  with 
all  lights  burning  and  expect  to  find  a  well  charged  battery  in  the  morning. 

Be  sure  that  all  wires  are  perfectly  insulated  and  not  in  contact 
with  any  moving  parts,  as  the  constant  rubbing  will  wear  off  the  insula- 
tion and  the  vibration  will  cause  the  connections  to  become  loose. 

All  permanent  connections  should  be  well  soldered,  all  stray  strands 
of  wire  removed  and  the  joints  properly  taped  in  order  to  prevent  loss 
of  current  from  short  circuits.  If  wires  must  be  run  where  there  is 


208  THE  GASOLINE  AUTOMOBILE 

liable  to  be  grease,  oil,  or  water,  they  should  be  protected  by  conduit 
or  other  oil  or  waterproof  material.  Either  oil  or  water  will  cause  the 
insulation  on  the  wire  to  be  of  very  little  value. 

The  generator  should  be  inspected  about  every  month  and  kept 
clean.  The  commutator  may  become  rough  and  blackened  and  should 
'be  cleaned  by  holding  a  piece  of  fine  sandpaper  against  it  while  rotating. 
Then  carefully  remove  all  metallic  particles  from  the  commutator  bars 
that  might  cause  a  short  circuit  between  them.  A  short  circuit  may  also 
be  caused  by  carbon  dust  from  the  brushes. 

The  brushes  should  always  have  a  perfect  bearing  surface  on  the 
commutator.  The  general  cause  of  a  poor  bearing  is  that  the  carbon 
brush  sticks  in  the  brush  holder.  It  may  be  taken  out  and  filed  down  so 
that  it  will  slide  easily  in  the  holder. 

When  putting  in  new  brushes,  make  sure  that  they  fit  perfectly 
on  the  commutator.  It  is  also  a  good  policy  to  use  only  the  brushes  sent 
out  by  the  manufacturer  of  the  machine. 

If  there  is  a  grounded  wire  in  the  machine,  or  if  a  commutator  segment 
becomes  loose,  the  armature  should  be  returned  to  the  factory  for 
repairs. 

The  carbon  brushes  contain  sufficient  lubricant  for  the  commutator 
so  that  it  is  not  necessary  to  use  any  oil  or  grease  of  any  kind.  If  grease 
or  oil  should  accumulate  on  the  brushes  or  commutator,  it  should  be 
wiped  off  with  a  dry  cloth. 

The  starting  motor  is  intended  to  perform  one  function  only,  viz., 
to  spin  the  engine,  and  should  only  be  used  for  such  purpose.  Any 
attempt  to  propel  the  car  by  the  starting  motor  or  indulge  in  the  needless 
use  of  same  will  result  in  trouble.  Such  experiments  are  of  no  material 
value  and  it  is  no  test  of  the  power  of  the  starting  motor,  but  simply 
imposes  an  extravagant  demand  on  the  battery.  If  these  practices  are 
indulged  in  they  will  result  in  a  complete  discharge,  which  is  detrimental 
to  the  life  and  service  of  the  storage  battery. 

146.  Starting  Motor  Troubles. — The  closing  of  the  starting  switch 
completes  the  circuit  between  the  battery  and  the  motor,  and  puts  the 
starter  in  operation.  If  the  starter  does  not  turn  the  engine  over,  release 
the  switch  at  once  and  ascertain  if  all  connections  are  tight  and  secure, 
and  inspect  the  battery.  If  the  starting  motor  turns  the  engine  over 
very  slowly,  it  is  evident  that  the  battery  is  weak  or  the  engine  stiff. 
If  the  starting  motor  is  turning  the  engine  over  at  a  reasonable  cranking 
speed  and  the  engine  does  not  fire,  remember  that  the  starting  motor  is 
performing  its  duty,  so  do  not  let  the  starting  motor  continue  to  crank 
the  engine  longer  than  necessary,  as  a  needless  drain  is  placed  on  the 
battery.  If  the  engine  does  not  fire,  it  is  evident  that  the  trouble  is 
confined  to  the  carburetor  or  ignition. 


STARTING  AND  LIGHTING  SYSTEMS  209 

147.  Generator  Troubles.— A  simple  test  to  determine  if  the  generator 
is  properly  operating  is,  first,  to  switch  all  the  lights  on  with  the  engine 
idle;  second,  to  start  the  engine  and  run  it  reasonably  fast.     If  the  lights 
brighten  perceptibly  after  starting  the  engine,  it  proves  that  the  generator 
is  properly  delivering  current.     This  test  must  necessarily  be  conducted 
in  the  dark,  either  in  the  garage,  or  preferably,  at  night  time.     Generator 
troubles  will  be  manifested  by  dim  lights  when  the  engine  is  running  at  a 
medium  rate  or  by  failure  to  keep  the  battery  charged.     The  trouble 
may  be  caused  from,  first,  grounds  or  short  circuits  in  the  field  windings; 
second,  increased  resistance  in  circuit,  caused  by  dirty  commutator  or 
brushes,  weak  brush  springs  or  poor  material  in  the  brushes  (poor  ma- 
terial in  brushes  causes  sparking  and  overheating) ;  third,  grounds  in  the 
armature,   caused  by  defective  insulation  or  carbon  deposits  on  the 
commutator  short-circuiting  the  copper  bars;  fourth,  circuit  breaker  or 
regulator  not  properly  adjusted  so  that  the  battery  is  not  cut  in  at  proper 
time.     The  contact  points  may  become  dirty  or  corroded  or  may  be 
burned  by  an  excess  of  current,  generally  from  a  reverse  current  from 
the  battery. 

148.  Battery  Troubles. — Battery  troubles  may  be  detected  by  failure 
to  turn  the  motor  or  by  the  lights  burning  dimly  when  the  engine  is 
stopped.     Battery  troubles  can  be  traced  to  improper    charging;  loss 
of  electrolyte;  short  circuits,  either  external  or  internal;  overloading, 
caused  by  using  light  bulbs  of  too  large  capacity;  burning  lights  when  not 
necessary;    and    propelling   car   with   starting   motor.     External   short 
circuits  may  be  caused  by  broken  insulation  so  that  two  bare  wires  come 
together  or  come  into  contact  with  the  frame  of  the  car  or  other  conducting 
material,  or  may  be  caused  by  acid  on  top  of  battery  forming  circuit 
between  terminals.     Internal  short-circuiting  is  explained  in  Art.  134. 

If  the  starting  motor  will  not  crank  the  engine,  the  trouble  may  be 
looked  for  as  follows: 

1.  Battery  discharged. 

2.  Broken  circuit  caused  by  worn  out  or  dirty  brushes  or  weak 
springs,  or  broken  connections  or  short  circuits  in  any  part  of  the  wir- 
ing or  switches.     A  dirty  commutator  will  have  the  same  effect  as 
dirty  brushes. 

If  the  starting  motor  cranks  the  engine  very  slowly,  the  trouble 
may  be  caused  by  the  battery  being  partly  discharged  or  by  an  excess  of 
resistance  in  the  circuit.  The  increased  resistance  may  be  caused  by 
loose  connections  in  wiring,  poor  contacts  in  switch,  dirty  brushes  or 
commutator,  brushes  made  from  unsuitable  material  or  not  held  firmly 
on  the  commutator. 

149.  Winter  Care  of  Batteries. — If  the  car  is  not  to  be  used  for  some 
time,  as  in  the  winter,  the  batteries  should  be  inspected  before  the  car  is 


210  THE  GASOLINE  AUTOMOBILE 

used  for  the  last  time.  Water  should  be  added  to  the  cells,  if  necessary, 
so  that  it  will  thoroughly  mix  with  the  electrolyte  when  the  car  is  driven. 
When  the  car  is  laid  up,  the  specific  gravity  of  the  electrolyte  should 
register  from  1.27  to  1.29.  In  this  condition  there  will  be  no  danger  of 
freezing  in  any  climate.  The  battery  should  be  charged  every  two 
months  during  the  "out  of  season"  period,  either  by  running  the  engine, 
or  by  charging  from  an  outside  source.  If  either  of  the  above  methods 
is  impossible,  and  there  is  no  garage  convenient  that  is  equipped  for 
charging  batteries,  the  battery  may  be  allowed  to  stand  without  charging 
during  the  winter,  providing  it  is  fully  charged  at  the  time  the  car  is 
laid  up.  Much  better  results,  however,  and  longer  life  of  the  battery 
will  be  obtained  by  giving  the  periodic  charges.  The  wires  of  the 
battery  should  be  disconnected  during  the  "out  of  season"  period  in 
order  to  prevent  any  slight  leaks  that  might  occur  in  the  wiring. 

150.  "Don'ts"  on  Starting  Equipment. — Don't  disconnect  the  battery 
and  start  the  engine  up  with  any  of  the  lamps  in  circuit.  This  is  very 
important  as  the  battery  acts  as  a  voltage  regulator  and,  if  not  con- 
nected, the  lamps  or  fuses  in  the  circuit  connected  will  be  blown  out 
immediately,  due  to  heavy  rise  in  voltage  from  the  generator. 

Don't  attempt  to  work  around  the  lighting  system  without  dis- 
connecting the  battery  ground  and  winding  it  with  tape.  It  is  a  very 
easy  matter  to  touch  a  screw-driver  or  a  pair  of  pliers  from  a  live  wire 
to  the  frame  or  to  the  pipes  or  engine,  thereby  causing  short  circuit  and 
blowing  out  a  fuse.  When  the  work  is  finished,  replace  the  ground  wire 
before  starting  the  engine. 

Don't  try  to  repair  or  readjust  any  of  the  instruments  supplied. 
Leave  this  to  the  manufacturers  whose  experience  in  this  field  will  in- 
sure handling  the  job  in  a  better  manner  than  you  can. 

Don't  leave  the  starter  button  in  the  socket  while  the  motor  is  running. 

Don't  stamp  on  the  starter  button,  but  press  it  down  deliberately 
and  firmly. 

Don't  fail  to  go  over  the  wiring  occasionally  and  see  that  all  binding 
posts  are  tight  and  free  from  corrosion. 

Don't  fail  to  remember  that  the  mechanism  is  an  electrical  starter 
and  not  a  motor  for  vehicle  propulsion. 

Don't  expect  the  starter  to  spin  the  motor  at  a  maximum  cranking 
speed  if  the  battery  voltage  is  run  down.  Endeavor  to  run  the  car  with 
fewer  lights  for  a  while  and  allow  the  voltage  to  pick  up. 

Don't  abuse  the  electric  starter.  The  mechanism  is  strong  and 
durable  and  guaranteed  for  the  purpose  intended,  but  is  not  guaranteed 
against  rough  treatment  or  inexcusable  abuse. 

Don't  fail  to  inspect  all  terminals  occasionally  and  see  that  the 
tape  which  protects  these  terminals  from  short-circuiting  is  in  good 


STARTING  AND  LIGHTING  SYSTEMS  211 

shape.  In  case  this  has  become  unwrapped,  it  is  advisable  to  replace 
immediately  with  fresh  insulating  tape  of  good  quality. 

Don't  try  to  hook  up  additional  electrical  equipment  without  care- 
fully going  over  the  wiring  diagram  to  find  the  proper  place  for  such  a 
connection. 

Don't  fail  to  see  that  the  ground  wire  from  the  battery  has  a  good 
contact  between  the  terminal  and  frame. 

Don't  fail  to  carry  extra  fuses  and  lamp  bulbs. 


CHAPTER  IX 


AUTOMOBILE  TROUBLES  AND  REMEDIES 

151.  Classification  of  Troubles.— The  manufacturers  of  automobiles 
are  constantly  striving  to  simplify  the  design  and  construction  of  all 
parts  in  order  to  reduce  the  number  of  troubles  which  are  a  constant 
source  of  worry  to  the  automobile  owner  and  driver.  They  have  been 


HIGH  TENSION  CABLE 

Insulation   worn  off, 
cable  not  attached 

SPARK  PLUG 
Broken,  fouled,  loose,     \ 
gap  too  wide  "••^    A 

VALVE:  CAP--* 


WATER  SPACE 
Filled  with  sediment 


PRIMING  COCK 
I  Loose 


VALVE 

Pitted,  scored.     ~~~~- 
covered  with  carbon 

MANIFOLD  JOINT-^ 
Not  tight 

VALVE  STEM — 

Bent,  stuck 

VALVE  SPRING 

Too  weak,  broken, 
out  of  place 

CLEARANCE- 

To  much  or  too  /it tie 

THROTTLE.    VALVE 
Disconnected  from 
throttle  valve  rod 

GASOLINE  FLOAT^ 
Soaked  or  logged 

FLOAT    VALVE."' 
Stem  bent  seat 
leaks,  valve  stuck 
on  seat 

GASOLINE  NEi 

VALVE: 

Bent  or  stutk 

CAM 
Contour  worn 


^P/STON  RINGS 
Loose,  broken, 
misplac.ec/ 

^PISTON 

Worn,  too  loose, 
out  of  round ', 

—  WRIST  PIN 
Worn,  loose 

— CYLINDER   WALLS 
Scored,   worn 

..D/STRIBUTOR 

Dirty 


T/MER  LEVER 


-  INTERRUPTER 
OR  TIMER 

Contact  points  not 
proper/y  adjusted 


TIMING  GEARS ' 
Gears  not  meshed 
properly 


CRANK  PIN 

Worn,  out  of 
round 


CONNECTING  ROD 
BEARING 
Loose,  worn 


'-CRANK  SHAFT 
Bearings  worn 

FIG.  236. — Chart  showing  location  of  common  mechanical  troubles  of  engines. 


quite  successful  in  reducing  troubles  to  a  minimum;  as  a  matter  of  fact, 
the  possible  troubles  on  the  modern  car  are  now  few  in  number  com- 
pared to  those  of  not  a  great  many  years  ago.  The  troubles  now  com- 
monly experienced  are  those  inherent  in  every  man-made  machine  which 
is  subject  to  the  wear  and  tear  of  everyday  use. 

213 


214  THE  GASOLINE  AUTOMOBILE 

It  is  obviously  impossible  in  many  cases  to  give  a  direct  statement  of 
a  cure  for  all  of  the  various  symptoms  which  are  likely  at  some  time  or 
other  to  confront  the  motorist,  as  some  symptoms  may  be  due  to  any 
one  or  more  of  several  different  causes.  All  that  can  be  done  is  to  offer 
a  few  general  suggestions  which  will  assist  him  to  diagnose  his  own 
specific  troubles  and  apply  the  proper  remedy. 

The  automobile  is  a  fine  piece  of  machinery  and  the  service  from  it 
will  depend  upon  the  care  and  attention  given  to  it.  Many  of  the 
troubles  on  the  modern  automobile  are  due  to  uncalled  for  adjustments 
and  investigations  by  the  motorist.  Although  good  care  and  attention 
must  be  given  in  order  to  get  efficient  service,  it  is  good  policy  to 
leave  well  enough  alone  and  not  do  any  unnecessary  tampering,  nor 
try  to  improve  upon  the  operation  or  construction  as  planned  by  the 
manufacturer. 

The  more  common  motor  car  troubles  can  be  divided  into  the  follow- 
ing general  headings: 

I.  II.  III. 

Power  plant  troubles  Transmission  troubles  Chassis  troubles 

(a)  Mechanical  parts  of  engine.  (a)  Clutch.  (a)  Wheel  hubs. 

(6)  Carburetting   and   gasoline  (6)   Change  gears.  (6)  Steering  gear. 

system.  (c)   Differential.  (c)   Brakes. 

(c)  Ignition.  (d)  Rear  axle.  (d)  Springs. 

(d)  Lubricating  and  cooling.  (e)   Tires. 

(e)  Starting  and  lighting. 

152.  Power  Plant  Troubles.— Any  derangement  in  the  power  plant 
will  show  itself  by  one  of  the  following  symptoms.  Under  each  symp- 
tom is  given  the  common  causes  with  a  reference  to  the  discussion  "on  the 
subject. 

(1)  Engine  Fails  to  Start. 

(a)  Poor  compression.     See  Art.  153. 

(6)  Engine  cylinder  flooded.     See  Art.  154(e). 

(c)  Carburetor  adjustment  not  right.     See  Art.  154. 

(d)  Water  in  gasoline.     See  Art.  154(j). 

(e)  Carburetor  frozen.     See  Art.  154 (g). 
(/)  Out  of  gasoline.     See  Art.  154(t). 
(g)  Engine  too  cold.     See  Art.  154(/). 
(h)  Ignition  switch  off. 

(i)    Foul  or  broken  plugs.     See  Art.  155(6). 

0')  Weak  batteries  or  magneto.     See  Art.  155(e,/,  and  g). 

(k)  Vibrators  not  properly  adjusted.     See  Art.  155(A). 

(0    Wiring  system  out  of  order.     See  Art.  155(d,  ;,  and  k.) 

(2)  Engine  Misses  at  Low  Speeds. 

(a)  Poor  compression.     See  Art.  153. 

(b)  Mixture  too  lean  or  too  rich.     See  Art.  154  (a  and  6). 


AUTOMOBILE  TROUBLES  AND  REMEDIES  215 

(c)  Spark  plug  gap  too  wide.     See  Art.  155(6). 

(d)  Spark  plug  cable  not  connected  or  short-circuited.     See  Art.  155  (d). 

(e)  Dirty  interrupter.     See  Art.  155  (jfc). 

(/)    Dirty  or  defective  spark  plug.     See  Art.  155(6). 
(g)  Vibrator  not  properly  adjusted.     See  Art.  155(h). 

(3)  Engine  Misses  at  High  Speeds  Only. 

(a)  Carburetor  not  set  for  this  speed.     See  Art.  154  (a  and  6). 
(6)  Bad  spark  plug.     See  Art.  155(6). 

(c)  Weak  valve  spring.     See  Art.  154(6). 

(d)  Timer  contact  imperfect.     See  Art.  155 (ft). 

(e)  Vibrator  points  dirty  or  burned.     See  Art.  155(h). 

(4)  Engine  Misses  at  All  Speeds. 

(a)  Carburetor  not  properly  adjusted.     See  Art.  154(a  and  6). 

(6)  Dirty  or  broken  plug.     See  Art.  155(6). 

(c)  Spark  plug  gap  not  right.     See  Art.  155(6). 

(d)  Poor  compression.     See  Art.  153. 

(e)  Loose  or  broken  terminals.     See  Art.  155(d). 

(/)  Weak  batteries  or  magneto.     See  Art.  155(e,  /,  and  g). 

(g)  Defective  wiring.     See  Art.  155(d). 

(h)  Coil  not  properly  adjusted.     See  Art.  155(h). 

(i)    Gasoline  feed  stopped  up.     See  Art.  154(6  and  h). 

0')    Needle  valve  bent  or  stuck.     See  Art.  154(6  and  h). 

(fc)  Water  in  gasoline.     See  Art.  1540')- 

(0    Poor  circulation.     See  Art.  156(6). 

(m)  Excessive  lubrication.     See  Art.  156 (a). 

(5)  Engine  Overheats. 

(a)  Lack  of  proper  circulation.     See  Art.  156 (a). 
(6)  Lack  of  proper  lubrication.     See  Art.  156 (a). 

(c)  Slipping  fan  belt  or  bent  fan  blades.     See  Art.  156(6). 

(d)  Too  rich  a  mixture.     See  Art.  154 (a). 

(e)  A  weak  mixture.     See  Art.  154(6). 

(/)    Running  with  spark  retarded.     See  Art.  155(0- 

(g)  Carbon  deposit  in  cylinders.     See  Art.  153(/)  and  155(m). 

(6)  Engine  Stops. 

(a)  Gasoline  tank  empty.     See  Art.  154(i). 

(6)  Water  in  gasoline.     See  Art.  1540'). 

(c)  Carburetor  flooded.     See  Art.  154(d). 

(d)  Lack  of  pressure  on  gasoline  tank.     See  Art.  154(i). 

(e)  Overheating  due  to  poor  circulation  or  lack  of  lubrication.     See  Art. 

156(o  and  6). 

CO    Short-circuiting  of  wires  or  terminals.     See  Art.  155(d  and  j). 
(g)  Disconnected  or  broken  wires.     See  Art.  155(d). 
(h)  Wet  batteries  or  magneto.     See  Art.  155(d  and  e}. 

(7)  Engine  Knocks. 

(a)  Carbon  deposits  in  cylinder  and  on  piston  heads.     See  Art.  153  (/)   and 

155  (m). 
(6)  Spark  too  far  advanced.     See  Art.  155(0- 

(c)  Running  motor  slow  when  pulling  heavy  load  on  direct  drive.     See  Art. 

155(0- 

(d)  Faulty  lubrication.     See  Art.  156 (a). 

(e)  Engine  overheated.     See  Art.  155(ra). 

CO   Loose  connecting  rod  bearings.     See  Art.  153(0). 


216  THE  GASOLINE  AUTOMOBILE 

(g)  Loose  piston.     See  Art.  153 (e). 

(h)  Loose  crank  shaft  bearing.     See  Art.  153(0). 

(8)  Engine  Will  Not  Stop. 

(a)  Short  circuit  in  switch. 

(6)   Magneto  ground  may  be  disconnected. 

(c)   Overheating  and  carbon  deposits.     See  Art.  155(m) 

(9)  Lack  of  Power. 

(a)  Poor  compression.     See  Art.  153. 

(6)  Too  weak  or  too  rich  a  mixture.     See  Art.  154  (a  and  6). 

(c)  Weak  spark.     See  Art.  155(e,  /,  g,  and  h). 

(d)  Lack  of  lubrication.     See  Art.  156 (a). 

(e)  Lack  of  cooling  water.     See  Art.  155(6). 
(/)   Lack  of  gasoline.     See  Art.  154  (ft  and  i). 
(g)   Dragging  brakes.     See  Art.  159(c). 

(A)  Slipping  clutch.     See  Art.  158(a). 

(**)    Flat  tires. 

(j)    Choked  muffler  causing  back  pressure. 

(10)  Back-firing  Through  Carburetor. 

(a)  Improper  needle  valve  adjustment.     See  Art.  154(6). 

(6)  Dirt  in  gasoline  passage  or  nozzle.     See  Art.  154(6  and  h). 

(c)  Inlet  valves  holding  open.     See  Art.  154(6). 

(d)  Excessive  temperature  of  the  hot  water  jacket  of  the  carburetor,  especially 

in  hot  weather.     This  can  be  remedied  by  shutting  off  the  water  from 
the  carburetor  jacket  and  cutting  off  the  hot  air  supply. 

(e)  Spark  retarded  too  far.     See  Art.  154(6)  and  155(m).   ' 

(11)  Firing  in  Muffler. 

(a)  Weak  mixture,  slow  burning  exhaust,  igniting  unburned  charge  from  pre- 
vious "miss."     See  Art.  154  (6). 
(6)  Valves  out  of  time. 

(c)  Too  rich  a  gasoline  mixture.     See  Art.  154(o). 

(d)  Occasional  missing  of  a  cylinder. 

(12)  Starter  Witt  Not  Operate. 

See  starter  troubles,  Chap.  VIII. 

153.  Mechanical  Troubles  in  Engine. — {a)  Poor  Compression. — Poor 
compression  is  one  of  the  common  causes  for  lack  of  power.  Unless  the 
compression  pressure  is  high  enough,  the  explosion  will  be  lacking  in  force 
and  the  engine  will  be  weak.  The  engine  can  be  turned  by  hand,  with 
the  ignition  off,  throttle  open,  and  the  compression  noted  in  each  cylinder, 
or  a  more  accurate  way  is  to  remove  the  spark  plug  and  screw  in  a  small 
pressure  gauge,  which  should  show  from  60  to  80  Ib.  at  the  end  of  the 
compression  stroke,  depending  on  the  make  of  engine.  Loss  of  com- 
pression is  commonly  due  to  leaky  or  improperly  seated  valves,  or  to  leaky 
joints.  Leaky  thread  joints,  valve  caps,  and  cracks  in  cylinder  are 
common  causes  for  loss  of  compression.  These  can  be  detected  by  a 
hissing  sound  or,  if  the  suspected  leak  is  covered  with  gasoline  or  oil,  the 
leak  will  show  itself  by  bubbling  through  the  oil.  If  the  trouble  can  not 
be  located  in  this  manner  attention  should  be  given  to  the  valves. 

As  a  rule,  the  intake  valve  requires  less  attention  than  the  exhaust 


AUTOMOBILE  TROUBLES  AND  REMEDIES 


217 


valve,  because  the  former  comes  into  contact  with  the  cool  fresh  fuel 
charges,  whereas  the  latter  is  apt  to  'become  fouled  and  burnt  by  the  hot 
and  dirty  exhaust  gases.  A  frequent  cause  of  leaky  valves  is  carbon 
deposit  on  the  valve  seats.  These  deposits  prevent  the  proper  seating 
of  the  valve.  The  remedy  is  to  clean  and  grind  them. 

b.  Grinding  Valves. — There  are  several  good  grinding  compounds  on 
the  market.  It  is  advisable  to  use  a  coarse  grade  in  the  first  operation  and 
then  to  finish  off  with  a  finer  one  to  give  a  polished  surface.  A  very  good 
homemade  mixture  is  obtained  by  making  a  thin  paste  of  a  couple  of 
tablespoonfuls  of  kerosene,  a  few  drops  of  oil,  and  enough  fine  flour 
emery  to  thicken  to  the  consistency  of  paste. 

The  valve  spring  must  be  removed  so  that  the  valve  may  be  lifted 
and  turned.  A  moderate  coating  of  the  paste  is  applied  to  the  bevel 
face  of  the  valve.  Next  rotate  valve 
back  and  forth  until  the  entire  bear- 
ing surface  is  polished  bright  and 
smooth  the  full  width  of  the  face.  The 
valve  should  never  be  turned  the 
whole  way  round.  Rotate  it  back  and 
forth  a  quarter  turn  at  most  under 
light  pressure,  lifting  it  up  frequently 
and  turning  it  halfway  round  before 
seating  it  again.  This  method  distri- 
butes the  friction  evenly  and  elimi- 
nates the  possibility  of  the  emery 
scoring  the  bearings.  If  no  valve 
grinding  tool  is  available,  the  use  of  a 
carpenter's  brace  or  bit  stock  is  recommended,  as  a  much  smoother 
movement  is  thus  obtained  than  by  using  a  screw-driver.  This  method, 
recommended  by  the  Overland  Company,  is  shown  in  Fig.  237. 

After  grinding  to  a  good  clean  seat  entirely  free  from  spots  or  pits, 
wash  the  valve,  valve  seat,  and  guide  thoroughly  in  gasoline.  If  the 
stem  is  rough  or  gummy,  smooth  it  up  with  emery  cloth  but  clean  it 
afterward  before  replacing  it  in  the  guide.  To  test  the  effectiveness  of 
your  work,  mark  the  valve  seat  in  several  places  with  a  lead  pencil  and 
turn  the  valve  around  a  few  times.  If  the  marks  are  entirely  rubbed  off, 
the  work  may  be  considered  well  done. 

(c)  Valve  Adjustments. — Poor  adjustments  of  the  valve  operating 
mechanism  may  cause  poor  compression,  even  if  the  valve  seats  have  been 
properly  ground  in.  The  valve  spring  may  be  broken  or  too  weak  to 
close  the  valve  on  its  seat  in  the  proper  time.  Sticking  of  the  valves  when 
open  may  also  be  the  cause  of  low  compression. 

The  clearance  between  the  valve  stem  and  push  rod  may  be  the  cause 


FIG.  237.— Valve  grinding. 


218  THE  GASOLINE  AUTOMOBILE 

of  considerable  trouble.  This  clearance  is  usually  about  the  thickness 
of  a  thin  visiting  card,  the  exact  amount  being  somewhat  different  for 
different  cars,  but  never  over  ^2  m- 

If  this  clearance  for  the  intake  valve  is  too  great,  the  lift  is  reduced, 
thus  preventing  the  proper  charge  from  getting  into  the  cylinder.  If  the 
exhaust  valve  lift  is  reduced  in  the  same  way,  it  will  be  more  difficult  for  the 
exhaust  gases  to  escape.  Too  much  clearance  also  changes  the  time  of 


Cam  Shaft 


FIG.  238. — Adjustment  of  push  rod  clearance. 

valve  opening  and  closing,  causing  the  valves  to  open  late  and  close  early. 
If,  on  the  other  hand,  this  clearance  is  too  small  or  entirely  absent,  the 
valve  will  open  early  and  close  late,  or  will  not  close  on  its  seat  at  all. 

As  the  valve  seats  are  lowered  by  continual  grinding,  the  clearance  is 
gradually  changed.  For  the  proper  operation  of  the  valves,  careful 
attention  should  be  given  to  this  clearance  space.  Figure  238  illustrates 
the  clearance  adjustment  on  the  Overland  car. 

A  weak  spring  on  the  exhaust  valve  may  have  a  marked  effect  on  the 


AUTOMOBILE  TROUBLES  AND  REMEDIES  219 

operation  of  the  engine.     The  exhaust  valve  then  opens  on  the  suction 
stroke  and  burnt  gases  are  again  drawn  into  the  cylinder. 

(d)  Valve  Timing.— It  is  essential  that  the  valves  be  properly  timed 
or  set,  in  order  to  have  the  engine  operated  properly.  The  valves  are 
set  at  the  factory  and  the  necessity  for  adjusting  the  timing  comes  as  the 
result  of  wear  on  the  valve  seats,  stems,  rods,  cams,  half-time  gears,  or  by 
improper  replacement  of  any  of  these  parts.  If  the  cam  shaft  has  been 
removed,  care  must  be  taken  to  get  the  gears  properly  meshed  when  re- 
placing it.  The  gears  are  marked  so  that  replacement  is  not  difficult. 
The  proper  method  of  replacing  the  gears  on  the  Ford  engine  is  shown  in 
Fig.  239.  It  will  be  noticed  that  there 
is  a  prick-punch  mark  on  one  tooth  of 
the  pinion  and  a  corresponding  mark 
on  the  large  gear.  Before  taking  a 
cam  shaft  out,  an  examination  should 
be  made  and  if  the  gears  are  not  so 
marked  it  should  be  done  before  they 
are  disturbed. 

If  the  clearances  are  properly  ad- 
justed for  the  push-rods  and  valve 
stems  and  if  the  timing  gears  are 
properly  meshed,  the  valves  should  be 
correctly  timed,  making  allowance  for 
wear  on  the  cam  faces.  Most  engines 
have  the  positions  at  which  the  valves 
start  to  open  and  close  marked  on  the 

circumference  of  the  flywheel.  These  FlG>  239.— Ford  cam  shaft  setting, 
points  should  be  opposite  the  pointer,  showing  marked  tooth  and  space  on 
usually  at  the  top  of  the  case,  when  il 

the  valves  start  to  open  and  close.  This  time  can  be  determined  by 
the  use  of  a  thin  sheet  of  tissue  paper.  By  placing  a  piece  of  the  paper 
in  the  clearance  space  between  the  push-rod  and  valve  stem,  one  can 
tell  when  the  valve  opens  or  closes. 

Valve  setting  is  an  adjustment  that  should  be  made  by  an  experienced 
mechanic  or  one  thoroughly  familiar  with  the  principles  of  the  four-stroke 
engine.  The  different  makers  have  found  by  trial  the  settings  that  will 
give  the  best  results  with  their  engines  and  cars.  These  settings  differ 
somewhat  according  to  different  conditions.  If  they  are  not  marked 
on  the  flywheel,  they  should  be  obtained  from  the  manufacturer. 

Figure  240  shows  the  approximate  crank  and  piston  positions  for 
the  valve  events.  The  inlet  may  be  opened  by  the  different  makers,  any- 
where from  top  center  to  20°  of  flywheel  motion  after  center.  The  inlet 


220 


THE  GASOLINE  AUTOMOBILE 


closes  from  25°  to  50°  past  lower  center.     The  exhaust  opens  35°  to  60° 
before  lower  center  and  closes  from  top  center  to  15°  past  center. 

(e)  Loose  Piston  or  Scored  Cylinder  Walls. — A  loose  piston  or  scored 
cylinder  walls  will  cause  a  marked  loss  of  compression.     If  the  piston  is 


Inlet  opens. 


Inlet  closes.  Exhaust  opens. 

FIG.  240. — Valve  setting  diagram. 


Exhaust  closes. 


not  too  loose,  slightly  larger  rings  may  be  put  on.  Sometimes  the 
blowing  can  be  remedied  by  using  a  heavier  cylinder  oil.  This  will 
to  some  extent  remedy  the  trouble  caused  by  scored  cylinder  walls, 
although  if  too  badly  cut,  they  must  be  rebored  and  new  pistons  or 
rings  fitted  in.  Again,  this  is  the  work  of 
an  experienced  mechanic. 

(/)  Carbon  Deposits  in  Cylinder. — After 
the  engine  has  been  run  for  some  time, 
carbon  deposits  are  liable  to  collect  in  the 
cylinder .  and  on  the  pistons,  especially  if 
too  much  lubricating  oil  or  gasoline  has 
been  used.  The  carbon  deposit  resulting 
from  too  much  lubricating  oil  is  a  sticky 
substance,  while  that  from  too  much 
gasoline  is  hard,  dry,  and  brittle.  These 
deposits,  if  allowed  to  collect,  become  hot 
from  the  heat  of  explosions,  and  cause 
preignition  of  the  fresh  charge  of  gas. 

The  best  methods  of  removing  carbon 
deposit  are  to  scrape  it  out  or  to  burn  it 
out  by  means  of  an  oxygen  flame.  The 
latter  method  is  quicker  and  by  far  the 


FIG.  241.— Scraping  the 
cylinders. 


most  convenient.     The  following  method  is  recommended  by  the  Over- 
land Company  for  the  removal  of  carbon  by  scraping : 

To  scrape  the  cylinders,  remove  both  inlet  and  exhaust  valve  caps. 
Fig.  241,  and  turn  the  motor  over  until  the  pistons  of  two  cylinders  are  at 
their  top  centers.  The  scraping  off  of  the  deposit  is  done  by  means  of 


AUTOMOBILE  TROUBLES  AND  REMEDIES  221 

tools  of  different  shapes,  the  tools  being  bent  so  as  to  reach  the  piston, 
head  and  the  sides  and  tops  of  the  cylinders.  Scrape  all  removed 
carbon  over  to  the  exhaust  valve  and,  when  through,  turn  the  motor  until 
the  exhaust  valve  lifts,  when  the  carbon  may  be  scraped  past  the  valve 
and  into  the  exhaust  passage,  whence  it  will  be  blown  out.  For  a  good 
job,  brush  the  surfaces  clean  and  make  sure  that  no  carbon  becomes 
lodged  between  the  exhaust  valve  and  its  seat.  Finally  wash  with 
kerosene. 

In  replacing  the  cylinder  plugs  over  the  valves,  put  graphite  grease 
around  the  threads;  this  will  make  a  compression-tight  joint  and  also 
make  it  easier  to  remove  the  plugs  the  next  time.  Likewise,  be  sure  to 
replace  the  copper  gaskets  under  the  plugs. 

It  is  an  excellent  plan  to  attend  to  removing  the  carbon  and  to  grind- 
ing the  valves  together  at  the  same  time. 

Kerosene  is  also  used  for  the  removal  of  carbon  from  the  cylinders. 
Pour  two  or  three  tablespoonfuls  of  kerosene  through  the  priming  cocks 
while  the  engine  is  warm.  It  has  a  strong  solvent  action  on  any  gummy 
binding  material  in  the  carbon  and  can  be  spread  over  the  entire  cylinder 
by  cranking  the  engine  a  few  times  around.  Some  motorists  inject  the 
kerosene  through  the  air  valve  of  the  carburetor  just  before  the  engine  is 
stopped  preparatory  to  putting  it  away  for  the  night.  Kerosene  will 
not  remove  a  hard  carbon  deposit  but  it  will  prevent  it  from  forming  if 
used  regularly  about  once  a  week. 

Running  the  engine  on  alcohol  for  a  few  minutes  is  another  device 
that  is  sometimes  used  for  burning  out  carbon  deposits. 

(0)  Bearing  Troubles. — The  common  bearing  troubles  are  those  caused 
by  the  bearings  becoming  worn  and  loose,  with  a  consequent  knocking. 
Faulty  lubrication,  clogged  oil  pipes  and  oil  holes,  and  dirty  oil  are  the 
main  causes  of  warm  bearings.  The  bearings  which  are  most  liable  to 
give  trouble  are  the  wrist  pin  bearings,  the  connecting  rod  bearings,  and 
the  main  crank  bearings.  After  a  bearing  has  been  excessively  hot,  it 
should  be  refitted  by  a  mechanic.  A  loose  bearing  can  be  tightened  on 
the  pin  by  removing  the  liners  or  shims,  or  by  being  refitted. 

154.  Carburetion  Troubles. — Improper  mixture  is  the  common  source 
of  carburetor  trouble.  The  mixture  is  either  too  rich,  that  is,  too  much 
gasoline  in  proportion  to  the  air,  or  too  weak,  that  is,  too  much  air  in 
proportion  to  the  gasoline. 

(a)  Mixture  too  Rich. — A  rich  mixture  shows  itself  by  black  smoke 
coming  from  the  muffler,  and  by  overheating  and  missing  of  the  engine. 
Not  only  is  fuel  wasted,  but  the  cylinders  become  fouled  and  carbonized. 
A  mixture  too  rich  at  slow  speeds  should  be  corrected  by  cutting  down 
on  the  gasoline,  and  at  high  speeds  by  increasing  the  auxiliary  air.  An 


222  THE  GASOLINE  AUTOMOBILE 

auxiliary  air  spring  which  sticks,  a  restricted  air  opening,  or  a  flooded 
carburetor  will  cause  an  overrich  mixture. 

(b)  Mixture  too  Weak. — A  weak  mixture  can  be  detected  by  back-firing 
through  the  carburetor  and  by  occasional  muffler  explosions.     A  weak 
mixture,  being  a  slow  burning  mixture,  is  still  burning  when  the  intake 
valve  opens  for  the  following  charge.     This  permits  the  flame  to  shoot 
back  through  the  manifold  into  the  carburetor.     A  weak  mixture  should 
not  be  confused  with  an  improperly  timed  intake  valve  which  opens 
before  the  burning  charge  has  been  exhausted.     If  the  intake  valve  has  a 
weak  spring  which  does  not  close  the  valve  properly,  it  may  permit  back- 
firing through  the  carburetor.     The  explosions  caused  by  the  valve  trouble 
are  usually  more  violent  than  a  back-fire  due  to  weak  mixture.     A  weak 
mixture  at  low  speeds  is  caused  generally  by  too  little  gasoline  and  at  high 
speeds  by  too  much  auxiliary  air  and  the  carburetor  should  be  adjusted 
accordingly. 

An  air  leak  in  the  manifold  connections  will  dilute  the  mixture  with  air 
and  cause  a  weak  mixture  and  back-firing.  These  leaks  should  be  remedied 
before  the  carburetor  adjustments  are  changed. 

A  stuck  or  bent  or  obstructed  gasoline  needle  valve  may  cause  a  weak 
mixture  by  shutting  off  the  supply  of  gasoline.  The  remedy  is  obvious. 

(c)  Color  of  Explosive  Flame. — By  opening  the  priming  cocks  on  the 
cylinders,  the  color  of  the  flame  can  be  seen  as  the  explosive  flame  issues 
out  of  the  cocks.     A  blue  flame  indicates  a  perfect  mixture,  a  red  flame 
indicates  an  excess  of  gasoline,  and  a  white  flame  indicates  an  excess  of  air. 

(d)  Flooded  Carburetor. — If  the   carburetor  float  becomes  gasoline 
soaked  or  filled  with  gasoline,  it  will  not  shut  off  the  gasoline  float  valve 
and  the  carburetor  float  chamber  will  become  filled  with  gasoline.    The 
remedy  is  to  take  the  float  out  and  if  it  is  made  of  cork,  have  it  dried  out, 
painted  with  shellac  and  baked.     If  of  the  hollow  metal  type,  have  the 
float  emptied  and  the  hole  soldered.     A  small  particle  of  dirt  under  the 
float  valve  will  also  cause  the  carburetor  to  become  flooded. 

(e)  Flooded  Cylinder. — If  the  engine  has  been  cranked  for  some  little 
time  and  too  much  gasoline  has  been  sucked  into  the  cylinders,  the  cylin- 
ders become  flooded  with  almost  pure  gasoline  which  condenses  in  the 
cold  cylinders.     This  charge  will  not  explode.     The  remedy  is  to  open  the 
priming  cocks  and  crank  the  engine  until  the  overrich  mixture  has  been 
expelled  or  diluted.     The  priming  cocks  can  then  be  closed  and  the  engine 
will  usually  start.     Flooding  of  the  engine  can  also  be  caused  by  priming 
the  cylinders  with  too  much  gasoline.     It  sometimes  happens  that  a 
flooded  engine  can  be  started  without  difficulty  after  standing  for  several 
hours.     The  excess  gasoline  has  evaporated  in  the  meantime. 

(/)  Cold  Weather  Starting. — In  cold  weather,  when  the  engine  is  stiff 
and  the  gasoline  is  hard  to  evaporate,  it  is  necessary  to  inject  a  little 


AUTOMOBILE  TROUBLES  AND  REMEDIES  223 

warm  or  high  test  gasoline  into  each  cylinder  through  the  priming  cocks. 
The  carburetor  may  also  be  heated  by  the  application  of  warm  cloths. 
The  priming  gasoline  can  be  heated  to  advantage  by  placing  a  bottle  of  it 
in  a  pan  of  hot  water. 

(0)  Frozen  Carburetor. — If  there  is  water  in  the  gasoline  this  water 
may  be  frozen  in  the  carburetor.     The  water,  being  heavier  than  the 
gasoline,  sinks  to  the  bottom  where  it  may  freeze  in  cold  weather.     To 
remedy  this  trouble  apply  hot  cloths  to  the  parts  affected.     Never  use  a 
torch  or  flame  of  any  sort  around  the  carburetor. 

(K)  Feed  System  Stopped  Up. — If,  after  priming,  the  engine  starts 
and  suddenly  dies  down,  the  gasoline  supply  may  be  exhausted,  the  feed 
pipe  may  be  clogged,  or  a  piece  of  dirt  may  have  worked  into  the  needle 
valve.  If  there  is  a  supply  of  gasoline  and  the  trouble  is  found  to  be  due 
to  dirt  in  the  feed  system,  the  feed  pipe  may  be  disconnected  and  the  dirt 
blown  out.  A  particle  of  dirt  in  the  needle  valve  may  be  removed  by 
screwing  the  valve  shut  and  then  opening  it  the  proper  amount.  This 
trouble  and  also  the  one  due  to  water  in  the  gasoline  can  be  prevented  by 
straining  the  gasoline  through  a  chamois  skin  before  putting  it  into  the 
main  tank. 

(1)  Loss  of  Pressure  on  Gasoline  Tank. — It  sometimes  happens  that 
if  a  pressure  gasoline  system  is  used,  the  pressure  becomes  too  low  to 
force  the  gasoline  from  the  main  tank  to  the  auxiliary  tank.     This  causes 
a  lack  of  fuel  at  the  carburetor.     A  hand  pump  is  usually  furnished  for 
increasing  this  air  pressure  on  the  tank. 

If  the  car  is  equipped  with  a  gravity  feed  system,  the  gasoline  may  fail 
to  run  to  the  carburetor  when  ascending  a  steep  hill.  It  sometimes  be- 
comes necessary  to  back  the  car  uphill,  in  which  case  the  gasoline  will 
run  to  the  carburetor  without  difficulty. 

(j)  Water  Logged  Carburetor. — It  sometimes  happens  that  the  carbu- 
retor becomes  loaded  with  water,  due  to  the  fact  that  it  can  neither  evapo- 
rate nor  get  out.  This  water  prevents  the  gasoline  from  getting  in. 
The  water  should  be  drained  from  the  carburetor  drain  cock. 

155.  Ignition  Troubles. — (a)  Locating  Defective  Plug. — If  one  of  the 
cylinders  is  missing  at  all  speeds,  the  ignition  is  at  fault.  The  cylinder 
can  be  located  by  opening  the  priming  cocks  and  watching  for  the  flame 
to  come  out.  The  cylinder  without  flame,  out  of  which  issues  only  a 
hiss,  but  no  short  report,  is  the  one  at  fault.  All  of  the  plugs  can  be  taken 
out  of  the  cylinders  and,  with  the  wires  attached,  placed  on  the  cylinder 
so  that  the  threaded  portions  only  are  in  contact.  By  turning  the  engine 
over,  the  defective  plug  can  be  detected. 

(fo)  Defective  Plugs. — A  defective  plug  may  be  broken,  oil  soaked, 
carbonized,  or  the  air  gap  between  terminals  too  much  or  too  little. 
If  the  plug  is  broken,  it  usually  must  be  replaced  by  a  new  plug.  A  plug 


224  THE  GASOLINE  AUTOMOBILE 

with  a  loose  center  electrode  may  sometimes  be  repaired.  If  carbonized 
or  sooted  up,  the  plug  may  readily  be  cleaned  with  a  stiff  brush  and  gaso- 
line. Do  not  scrape  with  a  knife,  as  it  merely  rubs  the  carbon  into  the 
surface  of  the  porcelain. 

The  gap  between  plug  terminals  should  be  between  >^0  and  %2  in. 
It  should  not  be  more  or  less  than  this  amount  for  efficient  ignition.  A 
smooth  dime  is  a  good  gage  to  use  for  setting  this  gap. 

(c)  Locating  a  Missing  Cylinder. — If,  after  the  plugs  are  found  to  be 
in  good  order,  one  or  more  of  the  cylinders  miss,  the  ones  at  fault  can  be 
located  by  detaching  the  wire  from  the  plug  and  holding  the  end  about 
34  in.  from  the  plug  binding  post.     A  missing  cylinder  will  show  no  spark, 
and  the  trouble  is  due  to  a  lack  of  secondary  current  in  the  wire  to  the 
plug.     Instead  of  detaching  the  wire  from  the  plug,  the  current  can  be 
short-circuited  by  placing  the  metallic  part  of  a  screw-driver  in  contact 
with   the   plug   binding   post  with  the  tip   of  the  screw-driver  about 
J4  m-  from  the  metal  of  the  cylinder.     As  before,  the  missing  cylinder 
will  show  no  spark.     Lack  of  current  at  the  plug  may  be  due  to  defective 
wiring,  weak  or  run  down  batteries,  poor  adjustment  of  vibrator  or 
circuit  breaker,  engine  out  of  time,    and   dirty   or   defective   magneto 
connections. 

(d)  Defective   Wiring  and  Switches. — If  there  is  no  current  at  the 
plug,  the  wiring  system  should  be  examined  carefully  for  dirty  and 
loose  terminals,  broken  connections,  and  oil  soaked  and  wet  wiring. 
If  the  insulation  has  been  worn  off,  the  current  is  liable  to  be  short-cir- 
cuited or  grounded  through  the  engine  or  frame  of  the  car.     Defective 
or  poor  contacts  at  switches  may  also  be  the  cause  of  no  current  at  the 
plugs. 

(e)  Dry  Batteries. — Weak  or  exhausted  batteries  are  a  common  source 
of  trouble.     If  the  batteries  are  suspected,  they  should  be  tested  with  a 
small  "ammeter."     If  any  one  of  the  dry  cells  shows  less  than  6  amp., 
it  should  be  taken  out  and  replaced  with  a  new  one.     One  weak  cell  will 
greatly  interfere  with  the  operation  of  the  others  in  the  set.     Occasionally, 
a  weak  dry  cell  can  be  livened  up  temporarily  by  boring  a  small  hole 
through  the  top  and  pouring  in  a  small  quantity  of  water,  or  better  still, 
of  vinegar.     The  effect  is,  however,  only  a  temporary  one. 

Dry  batteries  should  always  be  kept  perfectly  dry.  If  they  become  wet 
on  the  outside,  there  is  a  tendency  for  the  battery  to  be  short-circuited 
and  exhaust  itself.  Especially  is  this  true  if  water  spills  on  the  top  of 
the  battery  between  the  terminals. 

(/)  Storage  Batteries. — If  the  storage  battery  appears  dead  or  shows 
lack  of  energy,  it  may  be  due  to  one  of  the  following  causes  of  trouble: 
(a)  discharged;  (6)  electrolyte  in  the  jar  too  low;  (c)  specific  gravity  of 
electrolyte  too  low;  or  (d)  plates  sulphated.  These  troubles  are  fully 


AUTOMOBILE  TROUBLES  AND  REMEDIES  225 

treated  in  the  chapter  on  starting  and  lighting  under  the  heading  of 
Storage  Batteries. 

(g)  Magneto  Troubles. — If  the  ignition  trouble  has  been  located  in  the 
magneto  side  of  the  system  and  the  plugs  and  wiring  system  have  been 
found  in  good  working  order,  attention  should  be  turned  to  the  magneto 
itself.  The  distributor  plate  should  be  thoroughly  cleaned  with  gaso- 
line to  remove  any  foreign  matter  which  may  have  collected  after  con- 
siderable use.  After  attending  to  this,  it  should  be  determined  whether 
or  not  the  magneto  is  generating  current.  This  can  be  done  by  dis- 
connecting the  magneto  cables  and  watching  the  safety  spark  gap  while 
cranking  the  engine.  If  no  spark  appears  there  the  trouble  is  in  the 
magneto  itself. 

The  contact  points  may  be  pitted  or  burned.  They  should  be  filed 
until  they  meet  each  other  squarely.  Be  sure  that  the  adjustment  is  prop- 
erly made. 

The  carbon  or  collector  brushes  may  be  dirty  or  worn.  They  should 
be  cleaned,  or  if  badly  worn  replaced  with  new  brushes. 

It  occasionally  happens  that  the  magnets  become  weak  or  demagne- 
tized. They  may  possibly  be  placed  in  the  magneto  in  the  wrong  position. 
If  weak  or  demagnetized,  they  should  be  remagnetized  before  being  re- 
placed. Care  should  be  exercised  in  getting  the  like  poles  of  the  magnets 
together  on  the  same  side  of  the  magneto.  Most  magnets  are  marked 
with  an  "N"  indicating  the  north  pole. 

(h)  Coil  Adjustments. — A  frequent  cause  of  no  current  at  the  plug  is 
coil  trouble,  especially  where  a  vibrating  coil  is  used  for  each  cylinder. 
The  vibrator  points  become  pitted,  out  of  line,  and  burned,  making  good 
contact  impossible.  The  tension  on  the  vibrator  spring  becomes  changed, 
permitting  the  coil  to  consume  too  much  or  too  little  current. 

In  the  case  of  burned  or  pitted  points,  they  should  be  filed  flat  with  a 
thin  smooth  file,  or  hammered  flat  with  a  small  hammer.  In  either  case 
the  points  should  be  so  shaped  as  to  meet  each  other  squarely. 

If  it  becomes  necessary  to  adjust  the  tension  on  the  vibrators,  the  ten- 
sion should  be  entirely  taken  off  and  gradually  increased  until  the  engine 
runs  satisfactorily  without  missing.  It  is  very  important  to  have  all  the 
units  adjusted  alike.  This  can  be  easily  done  after  a  little  experience. 
The  most  accurate  method  of  coil  adjustment  is  with  a  coil  current  indi- 
cator by  which  the  amount  of  current  consumed  is  measured.  Coils 
are  built  to  consume  about  %  amp.  and  the  tension  should  be  adjusted  so 
that  the  current  consumption  of  each  coil  is  not  much  greater  than  this 
amount. 

(i)  Defective  Condenser. — A  sparking  between  the  points  of  a  vibrating 
coil  is  due  to  dirty  or  pitted  points,  loose  condenser  connections,  or  a  de- 
fective condenser.  If  the  latter,  a  new  unit  must  be  supplied, 


226  THE  GASOLINE  AUTOMOBILE 

(j)  Breakdown  of  Wires  or  Insulation. — If  no  current  is  obtained  in  the 
secondary  of  a  coil,  when  the  vibrator  is  working  as  it  should,  the  trouble 
is  probably  due  to  a  broken  wire  inside  of  the  coil.  It  sometimes  happens 
that  the  binding  post  wires  become  loose  from  the  post  just  inside  of  the 
coil.  If  only  a  slight  spark  can  be  obtained,  the  insulation  on  the  inside 
wire  may  be  broken  down,  thus  causing  a  short  circuit  of  the  current. 
Obviously  there  is  no  remedy  but  to  replace  the  coil. 

(k)  Timers  and  Commutators. — Trouble  in  the  timer  or  commutator 
usually  comes  from  oil,  water,  and  dirt  which  has  found  its  way  inside  of 
the  housing,  causing  a  short  circuit.  This  foreign  matter  should  be 
cleaned  out  of  the  timer  in  order  to  have  it  give  good  service.  After  a 
time,  the  contact  points  in  the  timer  become  worn  and  loose.  New  points 
should  be  put  in  and  all  loose  parts  tightened.  If  the  lost  motion  becomes 
too  great,  it  may  be  necessary  to  supply  a  new  timer. 

(1)  The  Spark  Setting. — If  the  engine  kicks  back  after  cranking,  the 
spark  is  too  far  advanced  an.d  should  be  retarded  so  that  the  spark  does 
not  occur  until  the  piston  has  passed  the  dead  center.  The  tendency  of 
an  early  spark  on  starting  is  to  cause  the  engine  to  start  backward.  Too 
early  a  spark  at  slow  speeds  will  make  the  engine  knock  and  will  cause  the 
car  to  jerk. 

A  retarded  spark  causes  the  engine  to  overheat  and  lose  considerable 
of  its  power.  There  is  no  advantage  of  retarding  the  spark  past  center, 
even  in  starting.  When  running  it  should  be  advanced  in  proportion  to 
the  speed.  ,  • 

On  cars  equipped  with  automatic  spark  advance,  the  troubles  due  to 
early  and  late  spark  are  not  experienced.  Preignition  from  other  causes, 
however,  may  occur  with  either  type  of  spark  advance. 

(m)  Premature  Ignition. — Premature  ignition  is  caused  by  particles  of 
carbon,  sharp  corners,  etc.,  becoming  incandescent  from  the  heat  of  ex- 
plosion and  igniting  the  charge  on  the  compression  stroke  before  the  spark 
occurs.  Premature  ignition  occurs  generally  when  the  engine  has  been 
loaded  quite  heavily  at  a  slow  speed,  as  when  going  up  a  steep  hill  on  high 
speed.  Any  engine  will  have  premature  ignition  if  it  becomes  excessively 
hot  under  low  speed  and  heavy  load,  but  the  tendency  to  preignite  is  much 
more  marked  if  the  cylinder  is  full  of  carbon  deposits.  These  carbon  de- 
posits should  be  cleaned  out  as  explained  before. 

156.  Lubricating  and  Cooling  Troubles. — (a)  Engine  Lubrication. — 
The  usual  lubricating  troubles  are  those  due  to  the  use  of  the  wrong  kind 
of  lubricating  oil  or  too  much  or  too  little  of  it.  An  engine  with  loose 
fitting  pistons  requires  a  heavier  oil  than  one  with  tight  fitting  pistons,  and 
an  air-cooled  engine  usually  requires  a  heavier  oil  than  a  water-cooled 
engine.  It  is  very  essential  that  a  true  gas  engine  cylinder  oil  be  used  for 
cylinder  lubrication  because  it  alone  satisfies  the  requirements.  Poor 


AUTOMOBILE  TROUBLES  AND  REMEDIES  227 

lubricating  oil  is  expensive  at  any  price  and  it  is  good  economy  to  use  the 
best  cylinder  oil  obtainable.  In  this  matter  the  recommendations  of  the 
manufacturer  should  be  followed  out. 

An  excess  of  lubricating  oil  shows  itself  by  a  white  bluish  smoke  com- 
ing from  the  muffler.  In  addition  to  this,  an  excess  of  lubricating  oil 
causes  the  formation  of  a  pasty  carbon  deposit  in  the  cylinder,  which  causes 
the  engine  to  overheat. 

The  important  things  to  look  after  are  to  be  sure  that  there  is  a  sufficient 
supply  of  oil  and  that  the  oil  pump  is  in  working  order.  The  crank  case 
should  be  drained  and  washed  out  with  kerosene  and  new  oil  put  in  every 
1000  miles. 

(6)  Poor  Circulation. — Poor  circulation  in  the  cooling  system  is  one  of 
the  common  sources  of  trouble  and  when  neglected  is  liable  to  give  the 
motorist  many  uneasy  moments.  The  water  system  must  be  kept  filled 
with  water.  This  is  of  especial  importance  in  the  thermo-syphon 
system,  in  which  the  water  level  must  at  all  times  be  above  the  return 
pipe  from  the  engine  to  the  radiator  in  order  to  have  the  circulation 
continue. 

A  worn  pump  may  cause  poor  circulation,  because  in  most  cases  the 
thermo-syphon  effect  in  a  forced  system  of  circulation  is  not  enough  to 
keep  the  water  moving  at  the  proper  rate. 

Sediment  in  the  radiator  and  scale  in  the  engine  jacket  may  seriously 
interfere  with  the  circulation  of  the  water.  Such  clogging  of  the  system 
comes  from  the  continual  heating  and  cooling  of  the  impure  water  used. 
This  emphasizes  the  desirability  of  using  pure  water  or  rain  water  in  the 
radiator.  The  sediment  and  hard  scale  may  be  removed  as  follows: 
Open  the  drain  cock  in  the  bottom  of  the  radiator  and  introduce  the  end 
of  a  hose  in  the  filler  of  the  radiator.  Run  the  motor  for  about  15  minutes 
and  the  fresh  water  from  the  hose  will  clean  out  the  loose  sediment  or 
scale  in  the  water  jackets  and  radiator.  Through  this  process,  a  supply 
of  fresh  water  is  constantly  entering  the  system  and  passing  through  the 
water  jackets  while  the  motor  is  running. 

Next,  dissolve  as  much  ordinary  washing  soda  as  can  be  dissolved  in 
enough  water  to  fill  the  radiator.  Then  run  the  motor  with  a  retarded 
spark  until  the  water  is  brought  up  to  the  boiling  point.  Allow  this  solu- 
tion to  remain  in  the  motor  and  radiator  for  several  hours,  after  which 
again  open  the  drain  cock  and,  with  a  hose,  again  flush  out  the  entire 
system  with  fresh  water  as  before.  In  extreme  cases  it  would  be  well 
to  repeat  this  process  several  times.  The  final  operation  of  flushing  out 
with  fresh  water  should  be  thoroughly  done.  If  any  of  the  washing  soda 
solution  is  left  in  the  motor  or  radiator,  it  may  result  in  undesirable 
chemical  action. 

When  rubber  hose  forms  a  part  of  the  circulating  system,  a  kink  or 


228  THE  GASOLINE  AUTOMOBILE 

twist  in  the  hose  may  possibly  cause  poor  circulation  of  the  water.  The 
inside  fibers  of  the  hose  also  tend  to  come  loose  and  clog  the  system. 

In  the  case  of  thermo-syphon  cooling  systems  or  in  air-cooled  motors, 
the  operation  of  the  fan  is  essential  to  the  successful  operation  of  the  cool- 
ing system.  If  the  fan  belt  breaks  or  slips,  or  the  fan  blades  are  bent,  the 
air  circulation  through  the  radiator  is  interfered  with  and  consequently 
the  water  is  not  properly  cooled. 

The  attention  which  must  be  given  to  the  cooling  system  in  winter  to 
prevent  freezing  has  been  thoroughly  taken  up  in  Chap.  V.  One  thing 
to  be  watched  in  winter  running  is  the  temperature  of  the  water.  If  the 
weather  is  excessively  cold,  the  water  may  be  cooled  below  the  efficient 
running  temperature  of  from  180°  to  200°.  In  this  case,  the  radiator 
front  should  be  partially  covered  in  order  to  keep  out  a  part  of  the  cold  air. 
This  will  also  keep  the  water  warm  for  a  longer  time  when  the  car  is 
standing. 

157.  Starting  and  Lighting  Troubles. — The  troubles  ordinarily  ex- 
perienced with  the  starting  and  lighting  systems  are  taken  up  in  the  chap- 
ter treating  of  those  subjects. 

158.  Transmission  Troubles. — (a)  Clutch  Slips. — Clutch  troubles  are 
about  the  same  in  either  the  cone,  plate,  or  multiple-disc  types.     The 
clutch  either  slips,  engages  harshly,  grabs,  or  refuses  to  release.     If  it 
slips,  the  full  power  of  the  engine  is  not  transmitted  and  the  clutch  becomes 
hot  from  the  friction.     In  the  cone  and  dry-plate  types,  a  coating  of  oil 
on  the  facings  will  cause  slipping.     The  wear  of  the  facing  or  weak  or 
broken  springs  will  cause  the  same  results.     If  the  slipping  is  caused  by 
grease  and  dirt,  the  clutch  leather  should  be  thoroughly  cleaned  with  a 
rag  dipped  in  kerosene. 

(6)  Clutch  Grabs. — If  the  clutch  engages  harshly  or  grabs  suddenly,  it 
may  be  due  to  the  drying  out  or  hardening  of  the  clutch  leathers.  A  dress- 
ing of  the  facing  with  neatsfoot  oil  or  castor  oil  will  make  it  soft  and  permit 
gradual  engagement.  If  the  clutch  springs  are  too  tight,  the  clutch  will 
"drag"  and  burn  the  leather  facing. 

If  a  multiple-disc  or  plate  clutch  is  designed  to  work  in  an  oil  bath,  it 
will  engage  harshly  or  grab  if  the  plates  become  dry.  The  clutch  will  also 
fail  to  disengage  when  the  pedal  is  pressed  down. 

(c)  Change  Gears  Stick. — If  the  change  gears  stick  when  attempt  is 
made  to  shift  from  one  gear  to  another,  the  shifting  members  may  be 
stuck  on  the  shaft.  If  the  gears  have  become  burned  or  teeth  broken  out, 
the  particles  of  metal  may  prevent  the  movement  of  the  sliding  member. 
Occasionally  the  shifting  lever  becomes  stuck  and  refuses  to  operate  the 
gears.  Under  ordinary  conditions,  the  change  gears  should  give  very 
little  trouble  if  due  attention  is  given  to  the  lubrication  and  care  to  their 
shifting  in  operation. 


AUTOMOBILE  TROUBLES  AND  REMEDIES 


229 


(d)  Differential  Troubles.— A  noisy  differential  and  driving  gear  is  due 
to  dirt,  lack  of  grease,  or  broken  or  worn  teeth.  In  some  cases  wear  can 
be  taken  up  by  the  proper  adjustments,  but  these  should  always  be  made 
by  an  experienced  mechanic.  The  differential,  as  a  rule,  will  give  very 
little  trouble.  A  break  in  the  differential  or  in  its  connections  to  the 
wheels  is  made  evident  by  failure  of  the  engine  to  propel  the  car.  If  the 
connection  to  either  wheel  is  broken  the  other  wheel  will  also  lose  its  power. 

159.  Chassis  Troubles. — (a)  Faulty  Alignment  of  Front  Wheels.— Most 
of  the  front  wheel  trouble  is  due  to  faulty  alignment.  The  following 
instructions  are  given  for  the  adjustment  of  the  front  wheels  and  bearings 
on  the  Overland  car:  The  front  wheels,  when  correctly  aligned,  are  not 
exactly  parallel,  but  "toed-in"  (Fig.  242).  To  test  their  proper  align- 
ment, jack  up  both  front  wheels  and  with  a  piece  of  chalk  or  a  lead  pencil 


FIG.  242. — Toed-in  and  cambered  front  wheels. 

held  in  a  fixed  position  against  the  tire  spin  the  wheels,  drawing  a  line 
around  the  tire  casing.  The  distance  between  the  lines  measured  at  the 
front  of  the  wheels  should  be  from  %  to  ^  in.  less  than  in  the  rear. 

"If  a  steering  knuckle  is  bent,  it  is  best  to  replace  it  with  a  new  one, 
because  bending  it  cold  will  not  always  restore  its  correct  shape,  while 
heating  it  may  make  it  too  soft  for  safety. 

"If  faulty  alignment  is  due  to  a  bent  steering  cross-rod,  it  may  be 
straightened  out  and  then  adjusted  by  loosening  the  lock-nut  and  screw- 
ing the  rod  in  or  out  of  its  yoke  end.  Be  sure  to  lock  the  nut  tightly 
after  adjusting. 

"The  front  wheels  are  also  'set,'  or  'cambered/  so  that  the  wheels  are  a 
little  closer  together  at  the  bottom  than  at  the  top.  This  arrangement  is 
desirable  on  account  of  the  fact  that  the  front  wheels  are  'dished'  so  as  to 
make  the  wheel  a  sort  of  flattened  cone.  This  'dish'  of  the  wheel  is  com- 
pensated by  the  'camber/  by  which  means  the  lowest  wheel  spoke  is  in  a 
vertical  position  with  relation  to  the  road  surface.  The  combined  'toe- 
ing-inr  and  'cambering'  makes  for  greater  strength  and  also  reduces  mate- 
rially the  effort  required  in  steering  the  vehicle.  The  camber  is  sequred  by 
inclining  the  axle  spindle  from  its  central  line,  and  no  adjustment  is  re- 
quired in  connection  with  it. 


230  THE  GASOLINE  AUTOMOBILE 

"To  see  whether  the  front  wheel  bearings  need  adjustment,  jack  up 
the  wheels.  Any  looseness  will  show  on  rocking  the  wheels  sideways. 
To  tighten  the  bearing,  spin  the  wheel,  at  the  same  time  screwing  down  the 
adjusting  nut  until  the  bearing  is  so  tight  that  it  will  stop  the  rotation  of 
the  wheel.  Then  back  off  the  nut  only  enough  to  allow  the  wheel  to  spin. 
Lock  in  this  position  and  the  bearing  will  give  the  best  service. 

"In  general,  a  somewhat  loose  bearing  is  to  be  preferred  to  one  that  is 
so  tight  that  the  rollers  are  likely  to  become  injured." 

(b)  Loose  Steering  Gear. — With  continued  use,  the  worm  or  screw  in  the 
steering  gear  will  wear,  and  a  looseness  of  the  wheel  will  result.     Means 
are  usually  provided  for  taking  up  this  wear.     Most  drivers  prefer  to  have 
a  small  amount  of  lost  motion  (about  %  in.)  in  the  wheel,  as  it  makes 
steering  easier  and  relieves  the  steering  gear  from  all  the  road  shocks. 
A  great  deal  of  steering  gear  trouble  and  wear  can  be  avoided  by  oiling 
all  the  joints  regularly.     This  important  point  is  too  often  neglected. 

(c)  Brakes. — It  is  very  necessary  that  the  brakes  be  kept  in  perfect 
working  order  at  all  times.     It  is  more  necessary  to  be  able  to  stop  the  car 
in  emergencies  than  to  start  it.     If  the  brakes  fail  to  hold,  it  may  be  that 
the  drum  and  band  facings  have  become  covered  with  oil  and  dirt,  or 
the  band  facings  may  be  worn.     In  the  latter  case,  new  facings  are  neces- 
sary in  most  cases,  but  adjustments  can  be  made  for  slight  wear. 

The  brakes  may  bind  or  stick,  due  to  the  tight  adjustments.  With 
tight  adjustments,  the  motor  is  pulling  the  car  against  the  friction  of  the 
brakes  at  all  times. 

If  the  brakes  are  not  adjusted  the  same  on  each  side  of  the  car,  there 
will  be  a  tendency  for  the  car  to  skid  when  the  brakes  are  applied.  The 
braking  effect  comes  on  only  one  wheel  and  this  tends  to  swing  the  car 
around.  Many  cars  are  provided  with  brake  equalizers  which  allow 
them  to  work  together. 

(d)  Springs. — After  a  car  has  been  run  for  some  little  time,  the  spring 
clips  become  loose  and  the  conditions  are  then  ideal  for  breaking  the 
springs.     Spring  breakage  occurs  mostly  with  loose  clips.     Consequently 
these  clips  should  be  tightened  every  once  in  a  while. 

When  springs  are  not  lubricated,  water  works  its  way  in  between  the 
leaves  and  causes  them  to  rust,  often  to  such  an  extent  that  they  become 
almost  like  solid  pieces.  This  causes  them  to  lose  much  of  their  spring 
action.  It  is  a  good  plan  to  jack  up  the  frame  of  the  car  occasionally, 
so  as  to  take  the  weight  off  the  springs,  and  insert  oil  and  graphite 
between  the  leaves.  It  is  also  a  good  plan,  about  once  a  year,  to  have 
all  the  springs  taken  apart,  the  surfaces  thoroughly  cleaned  and  coated 
with  a  thick  mixture  of  oil  and  graphite. 


CHAPTER  X 
OPERATION  AND  CARE 

160.  Preparations  for  Starting. — Before  starting  an  automobile  en- 
gine, the  driver  should  make  sure  that  there  is  plenty  of  gasoline  in  the 
tank  and  that  it  is  turned  on  so  as  to  flow  to  the  carburetor.     The  radiator 
should  be  filled  with  clean  water,  free  from  lime  or  other  form  of  matter 
that  will  have  a  tendency  to  coat  the  inside  of  the  radiator  when  the  water 
evaporates  and  thus  prevent  cooling  action.     Rain  water  is  best.     The 
driver  should  also  be  sure  that  he  has  plenty  of  lubricating  oil.    In  starting 
the  engine,  close  the  switch  on  the  battery  circuit,  or,  in  some  cases,  where 
a  high  tension  magneto  is  used,  the  engine  may  be  started  on  the  magneto. 
It  is  better,  though,  in  most  cases,  to  use  the  battery  circuit,  as  the  cur- 
rent there  is  always  available.     The  change  speed  lever  should  be  in  the 
neutral  position.     If  the  lever  is  so  that  the  gears  are  meshed,  cranking  the 
engine  would  start  the  car  in  motion,  and  engines  that  pick  up  easily  are 
liable  to  start  and  run  away,  especially  if  the  gear  shift  lever  is  in  the  first 
position.     It  is  also  advisable  to  have  the  emergency  brake  set.     This 
will  quite  often  prevent  runaways.     The  spark  lever  should  be  retarded, 
and  the  throttle  lever  slightly  advanced  before  cranking  the  engine.     As 
soon  as  the  motor  starts,  advance  the  spark  lever  about  two-thirds  of  the 
distance  around  the  quadrant,  and  retard  the  throttle  lever  so  that  the 
motor  will  not  race. 

161.  Cranking. — In  cranking  the  engine,  always  set  the  crank  so  as  to 
pull  up.     In  this  manner,  should  there  be  a  back-fire  the  crank  will  be 
pulled  down  out  of  the  hand;  whereas,  if  one  is  pushing  down  on  the  crank, 
the  back-fire  will  be  very  liable  to  cause  injury  to  the  driver's  wrist  or  arm, 
as  he  would  be  unable  to  get  away  from  it. 

After  an  engine  has  been  standing  for  some  time,  it  is  quite  probable 
that  it  will  not  get  gasoline  at  once,  due  to  the  gasoline  evaporating  or 
leaking  from  the  carburetor.  In  order  to  have  sufficient  gasoline  in  the 
mixing  chamber,  it  is  customary  to  raise  the  float,  which  allows  the  gaso- 
line to  overflow  into  the  mixing  chamber.  This  process  is  commonly 
called  "  priming"  or  "tickling"  the  carburetor  and  insures  a  rich  mixture 
in  starting. 

This  may  also  be  accomplished  by  opening  the  priming  cocks  on  the 
cylinders  and  pouring  a  few  drops  of  gasoline  directly  into  the  cylinders. 
If  there  are  no  priming  cocks  on  the  cylinders,  one  can  use  a  priming  spark 
plug. 

25  231 


232  THE  GASOLINE  AUTOMOBILE 

162.  How  to  Drive.— There  is  "good  form"  and  "bad  form"  in  driv- 
ing a  car  the  same  as  in  doing  anything  else.  One-half  the  pleasure  of 
motoring  comes  from  knowing  how  to  drive  easily.  Proper  driving  also 
means  minimum  strain  and  wear  on  the  car.  It  prevents  unnecessary 
stress  and  wear  on  the  motor  and  transmission  system,  and  saves  the  gaso- 
line and  oil.  In  starting  the  automobile,  the  object  is  to  have  the  car 
pass  from  a  stationary  position  into  rapid  motion  with  the  least  amount 
of  stress  on  the  motor  and  transmission,  and  also  with  the  most  comfort 
to  the  occupants  of  the  car.  In  doing  this,  a  steady  pull  should  be  main- 
tained on  the  driving  mechanism  from  the  point  where  the  driver  lets  in 
the  first  speed  until  the  car  is  under  full  headway.  Starting  with  a  jerk, 


FIG.  243.— Shifting  gears. 

or  passing  unevenly  from  one  speed  to  another,  strains  the  motor,  racks 
the  frame,  and  causes  various  troubles  in  the  driving  mechanism. 
Having  started  the  engine  with  the  gears  in  the  neutral  position,  the 
proper  method  of  gear  shifting  is  as  follows: 

Advance  the  spark  lever  about  two-thirds  of  the  way  around  the 
quadrant,  throw  out  the  clutch,  and  throw  the  speed  change  lever  in  the 
first  position,  as  shown  in  Fig.  243.  Let  the  clutch  in  easily  but  firmly 
and  increase  the  motor  speed  gradually,  either  by  the  foot  accelerator  or 
by  the  hand  throttle,  until  the  motor  picks  up  the  load.  Try  to  acceler- 
ate the  engine  as  the  clutch  is  let  in.  The  mechanical  act  of  shifting  gears 
is  very  simple,  but  the  knack  of  learning  to  perform  the  operation  rightly 
takes  practice.  As  you  engage  the  gears  for  any  speed  and  begin  to  let  in 
the  clutch,  give  the  motor  more  gas  at  the  same  time.  Once  you  have 
learned  to  do  this  properly,  you  will  never  have  to  give  it  a  thought. 


OPERATION  AND  CARE 


233 


In  changing  from  first  to  second  speed,  release  your  foot  accelerator  or 
throttle  hand  lever,  then  throw  out  the  clutch,  change  to  second  speed, 
and  again  let  in  the  clutch,  at  the  same  time  accelerating  the  engine  again. 
Repeat  the  same  operation  on  going  into  higher  speed. 

Just  before  shifting  gears,  the  engine  should  be  throttled  by  removing 
the  foot  from  the  accelerator,  so  that  the  two  gears  which  are  going  to  be 
meshed  are  running  at  the  same  speed.  This  permits  a  smooth  shifting 
of  gears,  and  also  prevents  the  motor  from  racing.  Then  as  the  clutch  is 
let  in  the  engine  should  be  accelerated  to  give  it  sufficient  power. 

When  the  car  is  in  high  speed,  assume  a  comfortable  easy  position. 
Do  not  sit  sideways  in  the  seat  nor  take  your  hands  from  the  steering 
wheel.  If  one  sits  in  an  easy  upright  position,  driving  does  not  become 
tiresome,  and  it  also  gives  a  person  better  control,  as  he  does  not  have  to 
move  from  his  position  in  order  to  operate  any  of  the  levers.  Also,  an 
erect  and  alert  driver  makes  a  better  appearance  than  one  who  slouches 
in  his  seat  and  handles  his  car  carelessly. 


FIG.  244. — Emergency  stop. 

163.  Use  of  the  Brakes.— The  operation  of  stopping  a  car  smoothly  is 
just  as  important  as  knowing  how  to  start.  The  best  results  are  obtained 
by  beginning  to  pull  up  your  car  early  enough,  so  as  to  apply  your  brakes 
gradually,  thus  bringing  the  car  to  a  stop  without  straining  the  mechan- 
ism or  jolting  the  passengers.  Do  not  wait  until  you  are  within  a  few 
feet  of  the  stopping  place  and  then  have  to  use  the  emergency  brake  or 
jam  the  brakes  down  hard.  Applying  the  brakes  hard  is  not  only  an 
unnecessary  strain  on  the  mechanism,  but  is  very  hard  on  tires  since, 
when  the  wheels  stop,  the  road  acts  as  a  file  on  the  tires. 


234  THE  GASOLINE  AUTOMOBILE 

Sometimes  it  is  necessary  to  make  an  emergency  or  quick  stop.  In 
doing  this  the  operator  does  not  take  time  to  slow  down  his  engine,  but 
presses  both  foot  pedals  and  applies  the  hand  emergency  brake  at  the 
same  time,  as  shown  in  Fig.  244.  In  pressing  both  pedals,  he  releases  the 
clutch  and  applies  the  service  brake,  and  the  braking  effort  is  further 
increased  by  the  application  of  the  emergency  brake. 

In  descending  steep  hills,  it  is  often  convenient  to  use  the  engine  as  a 
brake.  This  can  be  done  by  closing  the  throttle  and  shutting  off  the 
spark.  Then  by  leaving  the  clutch  in,  the  car  is  forced  to  run  the  engine 
against  compression  without  receiving  any  power  from  it.  The  gear 
shift  lever  may  be  left  in  either  high,  intermediate,  or  low  speed.  In  the 
low  speed  position  the  engine  will  have  more  of  a  braking  effect  than  in  the 
high  speed  position,  because  it  must  be  turned  much  faster  for  the  same 
speed  of  the  car.  If  the  grade  is  long  and  steep,  use  the  foot  and  emer- 
gency brakes  alternately.  This  equalizes  the  wear  on  them. 

164.  Speeding. — When  running  a  new  car,  do  not  speed  it  up  until 
you  are  absolutely  sure  of  your  ability  to  drive.     Furthermore,  any  new 
piece  of  machinery  should  not  be  run  at  high  speed  for  any  length  of 
time  until  its  bearings  have  had  a  chance  to  wear  to  a  smooth  fit.     A  few 
miles  of  racing  are  harder  on  the  bearings  of  a  car  than  several  days  of 
moderate  driving. 

165.  Care  in  Driving. — All  cars  have  low  and  intermediate  gears  for 
use  in  starting,  hill  climbing,  and  bad  roads.     A  good  rule  to  follow  in 
shifting  gears  is  to  shift  just  before  you  need  to  in  climbing  hills.     To 
attempt  to  climb  every  hill  on  high  speed  always  marks  the  amateur 
driver.     The  intermediate  gears  should  be  used  on  steep  hills,  even  if  they 
could  be  climbed  on  high  speed.     If  it  is  desired  to  climb  a  hill  on  high 
speed,  one  should  take  a  running  start  and  rush  up  the  hill.     In  going  over 
bad  roads,  it  is  better  to  shift  into  second  or  first  speeds  immediately. 
This  will  save  slipping  the  clutch,  which  is  a  bad  practice.     On  the 
lower  speeds,  one  can  control  the  speed  of  the  car  entirely  by  the  use  of 
the  throttle. 

In  going  over  bridges,  cross-walks,  railroad  tracks,  or  water-brakes,  it 
is  better  to  strike  them-  at  an  angle  than  to  hit  them  squarely.  This 
method  throws  the  strain  on  the  springs  successively  instead  of  all  at 
once  and  reduces  the  rebound  of  the  car.  In  going  through  sand,  it  is 
better  to  let  the  car  pick  its  way  and  not  try  to  hold  it  in  line  and  force  it 
to  make  a  new  track.  For  this  reason  a  little  play  in  the  steering  gear  is 
desirable. 

One  of  the  first  things  that  a  new  driver  learns  is  the  advantage  to  be 
derived  from  consideration  and  courtesy  extended  to  others  using  the 
public  highway.  Most  drivers  know  that  they  are  expected  to  turn  to  the 
right  when  approaching  a  vehicle,  or  to  the  left  in  overtaking  and  passing 


OPERATION  AND  CARE  235 

a  slow-moving  vehicle  going  in  the  same  direction.  In  meeting  another 
car  at  night,  dim  your  headlights  so  that  they  will  not  confuse  the  other 
driver. 

After  they  have  begun  to  realize  the  accuracy  with  which  a  car 
may  be  steered  and  the  ease  with  which  it  may  be  called  upon  to  pass 
another  vehicle,  possibly  approaching  from  the  opposite  direction,  it 
seems  natural  for  some  drivers  to  display  their  nerve  in  not  turning  from 
the  center  of  the  road  until  they  are  almost  upon  the  approaching  vehicle. 
Often,  however,  the  other  fellow  has  as  much  courage  and  takes  the  same 
stand,  and  in  the  confusion  which  very  frequently  follows,  either  one  or 
both  cars  are  damaged  on  account  of  collision. 

In  passing  vehicles  which  are  approaching,  as  large  a  margin  of  space 
as  possible  should  be  afforded,  and  in  passing  a  slow-moving  vehicle 
ahead,  pass  it  as  quickly  as  possible  and  without  cutting  in  short  ahead 
of  it. 

166.  Driving  in  City  Traffic.— The  lack  of  consideration  on  the  part  of 
a  few  careless  drivers  has  resulted  in  the  adoption  of  very  strict  muni- 
cipal regulation  governing  traffic.  Those  who  are  familiar  with  city 
traffic  regulations  and  apply  them  as  well  on  country  roads,  will  not  be 
likely  to  encounter  difficulties. 

The  burning  of  at  least  three  lamps,  including  two  head  or  side  and  one 
tail  lamp,  is  enforced  from  sun-down  to  sun-up  in  practically  every  state. 


FIG.  245.— Turning  to  the  right.  FIG.  246.— Turning  to  the  left. 

In  approaching  an  intersection,  either  in  the  city  or  in  the  country, 
where  a  clear  vision  of  the  road  approached  can  not  be  had  because  of 
buildings,  fences,  etc.,  which  obstruct  the  view,  the  car  should  be  slowed 
down  to  a  speed  at  which  it  can  be  readily  stopped  in  case  of  the  approach 
of  another  vehicle  from  either  side. 

In  turning  into  another  road  to  the  right,  the  driver  should  keep  his 
car  as  near  the  right-hand  curb  as  practicable,  as  shown  in  Fig.  245. 

In  turning  into  another  road  to  the  left  he  should  turn  around  the 
center  of  the  two  and  as  in  Fig.  246.  No  vehicle  should  be  slowed  or 
stopped  without  the  driver  thereof  giving  those  behind  him  warning  of  his 
intentions  to  so  do,  by  proper  signals. 

Often  drivers  of  horse-drawn  vehicles  become  confused  if  their  horses 
are  frightened  by  the  approach  of  an  automobile  and  in  drawing  up  the 


236  THE  GASOLINE  AUTOMOBILE 

horses  sharply  to  one  side  the  animals  are  liable  to  jump  or  rear,  with  the 
result  that  the  vehicle  may  be  overturned  and  the  automobile  injured  as 
well.  In  cases  of  this  kind,  it  is  better  to  stop  the  machine  entirely  and, 
if  necessary,  even  stop  the  motor. 

More  accidents  result  from  unwillingness  to  change  gears  than  from 
almost  any  other  cause.  Most  American  drivers  use  their  first  and  sec- 
ond speeds  only  in  starting  their  car.  They  allow  the  car  to  drift  along 
and  thus  get  into  a  tight  place  in  traffic  or  too  close  to  street  cars  and,  be- 
cause of  misjudging  the  speed  of  the  approaching  vehicle  or  their  selfish 
desire  to  crowd  out  another  car,  collisions  or  other  accidents  frequently 
result.  It  is  a  simple  operation  to  change  from  third  to  second  speed. 
It  increases  the  power  and  affords  the  possibility  of  a  great  deal  quicker 
acceleration  as  well.  The  second  speed  is  incorporated  for  a  purpose. 
It  is  seldom  that  we  are  in  such  a  hurry  that  we  can  not  spare  a  moment  to 
afford  absolute  safety. 

Accidents  are  not  due  to  one's  losing  control  of  the  car  in  many 
instances,  but  are  more  likely  due  to  one's  losing  control  of  himself. 
One  is  not  an  expert  driver  until  he  intuitively  performs  the  operations 
which  control  the  car  just  as  one  walks  or  reaches  out  for  an  object. 

167.  Skidding. — When  traveling  on  slippery  roads,  avoid  making 
sudden  turns;  also  avoid  sudden  application  of  the  brakes  or  sudden 
changes  of  power,  as  they  all  tend  to  cause  skidding. 

Most  skids  can  be  corrected  by  the  manipulation  of  the  steering  and 
brakes.  An  expert  driver  can  keep  his  car  straight  under  almost  any 
conditions,  but  it  is  impossible  to  explain  just  how  he  does  it,  except  that 
he  knows  his  car  and  becomes  almost  a  part  of  it.  Usually  the  rear  end 
skids  first,  and  in  the  right  hand  direction,  this  being  caused  by  the  crown 
of  the  road.  Under  such  conditions,  the  skidding  action  will  be  aggra- 
vated if  the  brakes  are  applied,  and  the  car  may  be  ditched  or  continue 
to  skid  until  it  hits  the  curb. 

The  correct  action  in  an  emergency  of  this  kind  is  to  let  up  on  the 
accelerator  pedal  and  thus  to  reduce  the  power  to  a  point  where  the  wheels 
are  rolling  freely  without  either  being  retarded  by  the  brakes  or  drawn 
ahead  by  the  engine.  If  the  car  recovers  its  traction,  the  power  may  be 
applied  gradually  and  it  will  be  advisable  to  steer  for  the  center  of  the 
road  again.  However,  if  the  car  continues  to  skid  sideways,  steer  for  the 
center  of  the  road,  applying  the  power  gently.  This  will  aggravate  the 
skid  for  the  moment,  but  will  leave  you  with  the  front  wheels  in  the  center 
of  the  road  and  the  car  pointing  at  an  angle.  By  so  doing,  you  can 
mount  to  the  crown  of  the  road  again  and  the  momentum  of  the  car  will 
take  the  rear  wheels  out  of  the  ditch  on  the  right  hand  side.  It  is  cus- 
tomary to  advise  turning  the  front  wheels  in  the  direction  that  the  car  is 
skidding  in  order  to  correct  the  action,  but  this  can  hardly  be  said  to  be 


OPERATION  AND  CARE  237 

advisable  in  most  cases,  as  the  amount  of  room  on  the  skidding  side  is 
somewhat  limited,  and  for  this  reason  the  explanation  given  above  will 
better  apply  to  such  a  condition. 

When  turning  a  corner  on  wet  asphalt  pavements  it  frequently  occurs 
that  the  front  wheels  skid.  In  a  case  of  this  kind,  immediate  action  is 
necessary.  It  will  be  found  that  by  applying  the  brakes  suddenly  for  a 
moment  so  as  to  lock  the  wheels,  the  rear  end  of  the  car  will  skid  in  the 
direction  in  which  the  car  is  to  be  turned.  This  will  help  the  action  of 
the  front  wheels  and  the  releasing  of  the  brakes  and  the  touch  of  the 
accelerator  will  bring  the  car  around  the  corner  without  any  over-travel 
of  the  front  end.  By  applying  the  brakes  in  this  way,  it  is  possible  to 
turn  the  front  wheels  in  the  direction  opposite  to  that  which  the  car  is 
to  be  turned  for  a  moment  while  the  rear  end  is  skidding.  When  the 
brakes  are  released,  it  is  plain  to  see  that  the  front  wheels  will  have  no 
tendency  to  skid  farther,  as  they  will  be  pointing  in  the  direction  which 
the  car  is  to  be  turned  and  the  rear  end  will  be  in  line  with  it,  due  to 
the  skid. 

Needless  to  say,  this  manipulation  requires  a  little  more  expertness 
than  the  correction  of  an  ordinary  skid  on  a  straight  road. 

Skidding  can  be  prevented  and  accidents  avoided,  also  the  life  of 
the  tires  lengthened,  if  one  will  learn  how  to  turn  his  car  out  of  street 
car  tracks  and  ruts.  Make  a  sharp  turn  of  the  front  wheels.  Do  not 
allow  the  wheel  to  climb  along  the  edge  of  the  rut  and  finally  jump  off 
suddenly,  and  do  not  attempt  to  climb  out  of  these  conditions  at  speed. 

Driving  a  car  around  a  sharp  corner  at  25  miles  an  hour  does  more 
damage  to  the  tires  than  15  or  20  miles  of  straight  road  work.  This  is 
an  economical  reason  why  one  should  drive  around  corners  cautiously 
and  slowly.  The  other  reasons  are  obvious. 

The  natural  inclination  of  the  driver  is  to  throw  out  the  clutch  in 
coasting  down  hill  or  driving  over  rough  roads.  This  should  not  be  done. 
Keep  the  motor  pulling  the  car  over  rough  roads.  Thus  it  keeps  every- 
thing taut  and  lessens  the  shock  and  jar  that  the  car  gets  through 
bumping  over  ruts. 

168.  Knowing  the  Car. — One  will  very  soon  become  accustomed  to 
all  of  the  noises  the  car  makes,  and  any  strange  sound,  be  it  ever  so  slight, 
will  be  immediately  perceptible. 

Much  of  the  satisfaction  that  an  automobile  gives  depends  upon  the 
driver.  If  he  neglects  his  automobile,  if  he  does  not  lubricate  it,  or  if 
he  tinkers  with  it  too  much,  he  is  bound  to  receive  unsatisfactory 
service. 

No  machine  can  be  absolutely  automatic.  All  things  must  wear  in 
time.  The  best  preventive  of  wear,  and  the  most  certain  thing  to  increase 
the  life  of  an  automobile,  is  proper  lubrication.  Remember  that  a  motor 


238  THE  GASOLINE  AUTOMOBILE 

car  is  like  any  piece  of  machinery  and  will  not  keep  in  good  running  con- 
dition without  a  reasonable  amount  of  care.  The  life  of  a  car  can  be  cut 
in  two  by  neglect  or  doubled  by  careful  use. 

One  should  familiarize  himself  thoroughly  with  all  the  lubricating 
points  of  the  car.  The  chart  in  Chap.  V  will  show  where  each  one  is  lo- 
cated. Make  the  lubrication  of  the  car  as  regular  as  the  eating  of  meals. 
If  one  does  this  he  will  not  have  any  complaint  to  make  of  his  car  becom- 
ing noisy  or  of  bearings  wearing  out.  If  he  does  not  do  it,  he  will  not  get 
the  satisfaction  from  his  car  that  he  expects.  Satisfaction  would  be 
greatly  increased  if  everyone  would  learn  the  details  of  his  machine,  that  is, 
learn  to  make  the  simple  examinations  and  adjustments.  Do  not  depend 
on  some  one  else  to  do  that  which  is  so  simply  done  and  which  one  can  get 
much  satisfaction  in  doing.  One  should  familiarize  himself  with  every 
detail  of  his  car  and  then  he  will  have  great  confidence  in  venturing  over 
any  road  at  any  distance  from  a  repair  station. 

In  learning  to  drive  a  car,  it  is  better  to  use  the  hand  throttle  for  the 
first  few  days  until  you  have  mastered  the  other  details  of  driving.  Then 
learn  the  use  of  the  foot  accelerator.  The  foot  accelerator  is  controlled 
by  a  spring  and  is  released  by  removing  the  foot.  This  will  slow  down  the 
car  to  the  point  where  the  hand  throttle  is  set.  In  using  the  foot 
accelerator,  keep  the  hand  throttle  set  at  a  point  where  the  engine 
will  just  pull  the  car.  Then,  when  the  foot  is  removed  from  the 
accelerator,  there  will  be  no  danger  of  an  accident  from  the  car's  not 
slowing  down. 

Never  allow  the  motor  to  race  when  it  is  idle.  "When  there  is  no  load 
on  the  engine  it  will  vibrate  unduly  at  high  speeds,  which  causes  exces- 
sive strains  and  makes  the  engine  and  car  noisy.  Racing  the  motor 
when  driving  can  be  avoided  by  learning  to  use  the  foot  accelerator  in  the 
proper  manner  in  relation  to  the  clutch  and  gear  shifts. 

169.  The  Spring  Overhauling. — The  greatest  trouble  with  the  average 
motorist  is  that  he  has  the  idea  that  all  the  attention  a  car  needs  is  to 
keep  it  full  of  gasoline,  oil,  and  water.  There  are  many  owners,  however, 
who  enjoy  making  their  own  adjustments  and  keeping  their  car  always 
in  good  condition  by  giving  it  frequent  attention.  After  a  car  has  been 
laid  up  for  some  time  the  oil  is  forced  out  of  the  bearings  and,  if  run  in 
this  condition,  considerable  damage  is  liable  to  result.  All  old  oil  should 
be  drained  off  and  the  case  thoroughly  washed  out  with  kerosene.  Hot 
kerosene  and  oil  should  be  poured  into  the  cylinders  to  cut  the  gummed 
oil  and  to  remove  any  rust  that  may  have  formed.  After  draining  off 
the  kerosene,  the  crank  case  should  be  filled  with  oil  to  the  upper  test 
cock.  Do  not  use  the  electric  starter  until  you  are  sure  that  the  motor 
is  free  to  turn.  Better  turn  the  motor  over  a  few  times  with  the  hand 
crank  first.  Clean  the  spark  plugs  by  washing  with  gasoline  and  a 


.  OPERATION  AND  CARE  239 

brush — never  scrape  them,  then  adjust  the  spark  gap  between  points 
to  about  3^2  in.  or  the  thickness  of  a  well  worn  dime. 

Test  for  leaks  around  the  valves  and  spark  plugs  by  squirting  oil  on 
the  joints  and  then  turning  the  engine  over.  If  there  are  any  leaks,  air 
bubbles  will  be  seen  in  the  oil. 

If  the  gasoline  does  not  flow  to  the  carburetor,  remove  the  feed  pipe 
and  blow  it  out;  also  clean  the  screen  in  the  bottom  of  the  carburetor. 
The  gasoline  flow  can  be  tested  by  holding  down  the  float. 

In  the  wet  type  multiple-disc  clutches,  the  oil  should  be  drained  off 
and  then  they  should  be  filled  with  kerosene.  Replace  the  plug  and 
start  up  the  motor.  Let  the  motor  run  for  a  few  minutes  during  which 
time  push  the  clutch  in  and  out  several  times.  Then  stop  the  motor, 
drain  off  the  kerosene,  and  fill  with  the  proper  amount  of  lubricant.  The 
transmission,  differential,  and  universal  joint  should  also  be  washed  out 
and  repacked.  Every  point  mentioned  on  the  lubrication  chart  of 
Chap.  V  should  be  cleaned,  adjusted  and  oiled. 

Electrical  System. — Remove  the  rotor  and  clean  its  bearings  with  gaso- 
line and  a  cloth,  then  rub  a  little  vaseline  on  the  race  very  lightly.  Clean 
the  breaker  points  with  a  fine  piece  of  emery  cloth  and  set  the  gap  to  the 
width  of  the  gauge,  or  about  ^4  in.  See  that  all  wiring  connections  are 
tight  and  free  from  corrosion.  It  is  a  good  plan  also  to  put  in  new  dry 
cells  and  be  sure  that  they  are  connected  up  properly. 

The  storage  battery  is  probably  the  most  delicate  part  of  the  car  and 
should  receive  very  careful  attention.  It  is  advisable  to  give  the  battery 
a  long  overcharge  at  the  beginning  of  the  season,  especially  if  the  car  has 
been  laid  up  for  some  time. 

During  the  out-of-season  period,  rust  will  accumulate  in  the  radiator 
and  engine  jacket,  and  should  be  cleaned  out.  To  do  this,  drain  out  the 
anti-freezing  solution  and  fill  the  radiator  with  a  solution  of  soda  and 
water.  With  this  solution  in  the  cooling  system,  run  the  motor  for  about 
10  minutes  and  wash  out  the  system,  following  the  instructions  of  Art. 
156(6),  Chap.  IX. 

The  leaves  of  the  springs  should  be  spread  apart  and  a  mixture  of  oil 
and  graphite  inserted. 

If  the  tires  have  been  removed  for  storage,  see  that  a  thorough  appli- 
cation of  soapstone  is  applied  to  the  inside  of  the  rims  to  prevent  their 
sticking  to  the  tires. 

An  easy  way  to  calculate  pressure  for  tires  is  to  multiply  the  diameter 
of  the  tire  in  inches  by  20.  For  example,  the  correct  pressure  for  a  3-in. 
tire  is  60  lb.,  and  for  a  4-in.  tire,  80  Ib.  A  tire  should  be  pumped  up  till  it 
becomes  perfectly  round  when  supporting  the  weight  of  the  car.  Of 
course  the  only  sure  way  of  getting  the  correct  pressure  is  with  the  use  of 
a  reliable  pressure  gauge. 


240  THE  GASOLINE  AUTOMOBILE 

170.  Washing  the  Car.— The  car  should  be  washed  before  the  mud  has 
a  chance  to  dry.     If  a  hose  is  used,  the  stream  should  be  tempered  or, 
better  still,  the  nozzle  should  be  taken  off  the  hose  and  a  slow  stream 
used.     Always  use  cold  water,  as  warm  water  will  injure  the  varnish. 
After  hosing  off  the  mud,  take  a  sponge  well  filled  with  water  and  gently 
dash  it  against  the  surface.     Never  rub  the  surface  when  washing,  as  it  is 
sure  to  scratch  the  polished  surface. 

After  the  mud  has  been  removed,  remove  any  grease  from  the  finish  by 
washing  with  suds  of  a  pure  white  soap.  This  should  be  done  with  a 
soft  sponge  and  as  little  rubbing  as  possible.  After  soaping,  rinse  with 
cold  water,  rub  dry,  and  polish  with  a  chamois  skin.  Do  not  have  the 
car  standing  in  the  bright  sunlight,  for  it  will  dry  too  rapidly  and  be 
streaked. 

A  new  car  should  be  washed  with  cold  water  before  it  gets  dirty.  The 
cold  water  will  help  to  set  the  varnish  and  prevent  the  accumulation  of 
dust. 

Cleaning  the  Reflectors. — When  lamp  reflectors  become  dirty  do  not 
wipe  them,  but  use  a  stream  of  cold  water  to  remove  the  dust  or  dirt 
and  permit  the  reflectors  to  dry  by  air  only.  The  reflectors  are  silver 
plated.  The  silver  becomes  scratched  when  the  reflector  is  wiped,  even 
with  very  soft  material.  If  reflectors  become  dull  after  long  service,  they 
should  be  polished  by  using  chamois  with  a  light  application  of  red  rouge 
or  crocus.  The  chamois  should  be  very  soft  and  free  from  wrinkles.  If 
a  wad  of  cotton  or  waste  (about  the  size  of  an  egg)  is  placed  within  the 
chamois,  a  smooth  surface  for  wiping  can  be  obtained.  Red  rouge  or 
crocus  is  used  by  j ewelers  for  cleaning  watch-cases.  When  properly  placed 
on  chamois,  it  will  not  scratch  the  reflector.  Moisten  the  chamois 
with  alcohol,  then  apply  the  rouge  or  crocus  to  the  chamois  and  wipe  the 
reflector  with  a  continuous  rotary  motion,  but  do  not  press  too  hard. 
The  polishing  marks  will  be  very  noticeable  if  other  than  a  rotary  motion 
is  used.  The  efficiency  of  old  reflectors  will  be  increased  if  they  are  silver 
plated.  This  should  be  done  by  a  lamp  manufacturer  or  a  reliable 
silver-plater. 

171.  Care  of  Tires. — The  following  few  suggestions  will  apply  to 
pneumatic  tires  in  general.     The  various  sizes  of  tires  are  constructed 
for  the  purpose  of  carrying  up  to  certain  maximum  loads  and  no  more. 
Owners    should    realize,    therefore,    that    overloading    a    car    beyond 
the  intended  carrying  capacity  of  the  tires  is  sure  to  materially  shorten 
their  life. 

Do  not  turn  corners  or  run  over  sharp  obstructions,  like  car  tracks, 
at  a  high  rate  of  speed.  Such  practice  is  sure  to  strain  or  possibly 
break  the  fabric,  with  the  result  that  the  further  life  of  the  tires  will  be 


OPERATION  AND  CARE  241 

limited.  Remember  that  most  tire  troubles  are  the  result  of  abuse  more 
than  use. 

In  case  of  puncture  the  car  should  be  stopped  at  once  and  the  tube 
repaired  or  replaced.  The  tire  should  also  be  examined  carefully  and  the 
cause  of  the  puncture  ascertained,  and  the  nail,  glass,  or  whatever  it  may 
be,  should  be  extracted.  Before  replacing  the  tire  on  the  wheel,  examine 
the  inside  of  the  casing  to  see  that  the  cause  of  the  puncture  is  not  still 
protruding,  because,  if  allowed  to  remain,  it  would  continue  to  cut  the 
inner  tube.  It  is  also  advisable  to  look  over  the  outside  of  your  tires  fre- 
quently and  take  out  any  pieces  of  glass  or  other  particles  which  may 
have  become  imbedded  in  the  casing,  as  they  are  liable  to  work  themselves 
in  and  finally  puncture  the  inner  tube. 

A  puncture,  gash,  or  cut  sufficiently  deep  to  expose  the  fabric  should 
have  a  vulcanized  repair  made  without  delay.  Otherwise,  water  and  dirt 
will  soon  ruin  the  whole  tire,  the  threads  acting  as  a  conductor  for  the 
moisture,  the  fabric  thus  becoming  rotted. 

A  bruise  is  an  injury  to  the  carcass  of  a  tire  caused  by  violent  contact 
with  an  irregularity  which  tears  the  fabric.  Usually  the  injury  does  not 
show  at  once.  However,  the  structure  of  the  tire  is  permanently  weak- 
ened at  the  injured  spot,  and  eventually  a  blowout  will  occur.  Even 
the  most  careful  and  skillful  driver  cannot  avoid  bruises  altogether.  But 
if  your  tires  are  properly  inflated  and  you  strike  an  obstruction,  the  tire 
has  the  resiliency  of  the  air  behind  it  to  aid  in  resisting  the  impact  of  the 
blow  and  the  effect  is  likely  to  be  less  serious. 

Experience  has  taught  the  careful  driver  to  carry  one  or  more  spare 
tubes,  as  a  cemented  roadside  repair  will  not  always  hold,  especially  in 
warm  weather,  as  the  heat  generated  in  the  tire  may  loosen  the  patch. 
When  touring,  a  spare  casing  should  always  be  carried.  It  should  be 
strapped  tightly  to  the  tire  holder,  otherwise  it  will  chafe. 

Spare  tubes  should  be  kept  lightly  inflated.  This  keeps  them  in  good 
condition  and  prolongs  their  life.  They  should  not  be  stored  in  a  greasy 
tool-box  under  any  circumstances. 

Excessive  weight  on  a  casing  will  break  down  the  fabric  in  the  side 
walls,  and  if  persisted  in,  a  blow-out  is  apt  to  result.  When  this  occurs, 
the  casing  is  likely  to  be  so  badly  damaged  as  to  be  beyond  repair.  If 
your  roads  are  very  rough  and  stony,  or  if  you  are  carrying  heavy  weights 
in  your  car,  it  is  better  to  equip  the  car  with  a  set  of  extra-size  tires. 
You  can  get  larger  tires  which  will  fit  your  rims. 

Pneumatic  tires  are  designed  to  carry  loads  in  proportion  to  their  cross- 
sectional  area  and  diameter.  They  should  never  be  overloaded.  Fol- 
lowing is  given  a  table  of  the  various  tire  sizes  and  the  weight  each  tire 
should  carry.  Weigh  the  car,  and  if  the  tires  are  carrying  more  than 
their  rated  load  put  on  larger  tires. 


242 


THE  GASOLINE  AUTOMOBILE 


Size  of  tires 

Load  per  wheel  in 
pounds 

Size   of  tires 

Load  per  wheel  in 
pounds 

2^  in.  all  diam. 

225 

30  X  4  in. 

550 

3  in.  all  diam. 

350 

32  X  4  in. 

650 

28  X  3M  in. 

400 

34  X  4  in. 

700 

30  X  3K  in. 

450 

36  X  4  in. 

750 

32  X  3^  in- 

550 

32  X  4K  in. 

800 

34  X  3^  in- 

600 

34  X  4H  in- 

900 

36  X  3^  in. 

600 

36  X  4^  in. 

1000 

All  5  in. 

1000  or  over. 

If  the  car  is  not  used  during  the  winter,  it  is  better  to  remove  the  tires 
from  the  rims,  keeping  casings  and  tubes  in  a  fairly  warm  atmosphere 
away  from  the  light.  It  will  be  better  to  slightly  inflate  the  tubes,  as 
that  keeps  them  very  nearly  in  the  position  in  which  they  will  be  used  later 
on.  Before  the  tires  are  put  back,  the  rim  should  be  thoroughly  cleaned 
and  any  rust  carefully  removed;  a  coat  of  paint  or  shellac  is  also  advised. 
If  the  tires  are  not  removed  and  the  car  is  stored  in  a  light  place,  it 
will  be  well  to  cover  the  tires  to  protect  them  from  the  strong  light,  which 
has  a  deteriorating  effect  on  rubber. 

The  greatest  injury  that  can  be  done  to  tires  on  a  car  stored  for  the 
winter  is  to  allow  the  weight  of  the  car  to  rest  on  the  tires.  The  car 
should  be  blocked  up,  so  that  no  weight  is  borne  by  the  tires,  and  the 
tires  should  then  be  deflated  partially.  This  will  relieve  the  tires  of  all 
strain,  so  that  in  the  spring  they  should  be  no  worse  for  the  winter's 
storage. 

Extra  casings  carried  on  the  car  should  be  covered  to  protect  them  from 
the  sunlight,  which  has  an  injurious  effect  on  rubber.  Do  not  place  your 
extra  tubes  where  they  will  come  into  contact  with  tools  or  oil.  Carry 
the  tubes  in  a  tube  bag.  It  is  a  good  plan  to  tie  a  piece  of  cloth  around 
the  valve  stem  before  placing  the  tube  in  the  bag.  This  will  prevent  the 
possibility  of  the  stem  injuring  the  rubber. 

Bear  in  mind  that  heat,  light,  and  oil  are  natural  enemies  of  rubber. 
When  grease  comes  into  contact  with  your  tires,  it  should  be  removed 
immediately  with  gasoline. 

Fast  driving  and  tire  economy  have  absolutely  nothing  in  common. 
High  speed  and  high  bills  for  tire  maintenance  usually  go  hand  in  hand. 
It  stands  to  reason  that  the  wear  and  tear  on  tires  is  far  greater  when  a  car 
is  driven  at  a  high  rate  of  speed  than  when  it  is  used  at  a  moderate  pace. 
In  addition  to  the  increased  force  with  which  a  wheel  strikes  an  obstruc- 
tion, when  rolling  at  an  excessive  speed,  fast  driving  generates  increased 
heat  in  your  tires,  causing  disintegration. 

Shifting  Tires— Tires  that  show  wear  on  one  side  from  use  on  rutty 


OPERATION  AND  CARE 


243 


roads  or  from  driving  in  car  tracks  should  be  turned  around.  It  is  also 
a  good  plan  to  place  the  rear  tires  on  the  front  wheels  when  they  begin  to 
show  age.  Rear  tires  carry  more  than  half  the  weight  of  the  car,  get  the 
roughest  usage,  and  are  also  the  driving  tires,  so  that  they  naturally  wear 
more  rapidly  than  the  front  tires,  which  are  simply  subject  to  a  rolling 
action  and  usually  sustain  less  weight.  A  sprung  axle  will  often  cause 
quick  wearing  of  a  tire,  for  the  reason  that  the  tire  is  running  at  an  angle 
with  the  direction  of  the  car.  This  necessarily  sets  up  a  sliding  and  scrap- 
ing on  the  road  surface.  If  the  surface  of  one  tire  looks  as  if  it  has  been 
sandpapered,  examine  the  alignment  of  the  wheels. 


FIG.  247. — Broken  fabric. 

172.  Tire  Troubles— Broken  Fabric.— On  the  inside  of  the  casing 
shown  in  Fig.  247  will  be  noticed  a  break  in  the  fabric.  This  is  the  result 
of  the  blow  received  by  the  tire  in  hitting  a  stone,  rail,  or  something  of 
that  sort  at  high  speed.  While  no  permanent  mark  may  be  left  on  the 
outside  of  the  tire,  especially  if  the  object  is  smooth  and  blunt,  the  fabric 
inside  may  give  way  under  the  abnormal  strain  of  such  a  blow.  This  does 
not  indicate  that  the  tire  was  in  any  way  defective. 

Sometimes  a  tire  may  be  run  weeks  after  the  fabric  is  broken  from  the 


244  THE  GASOLINE  AUTOMOBILE 

bruise  before  the  blowout  occurs.  It  has  even  happened  in  a  garage,  with 
the  car  standing  still.  Sometimes  the  break  will  exist  only  in  a  few  of  the 
plies  of  fabric,  which  will  pinch  the  inner  tube,  allowing  the  tire  to  deflate 
gradually. 

Blowouts.— Few  people  realize  the  tremendous  pressure  tending  to 
rupture  a  tire  and  the  consequent  great  strength  that  must  be  given  any 
repair  that  is  to  be  effective.  This  is  especially  true  in  cases  of  blow- 
outs. Figure  248  shows  a  tire  that  has  blown  out  due  to  ineffective  repairs. 


FIG.  248.— Blow-out  from  ineffective  repairs. 

It  originally  had  a  small  cut  extending  clear  through  the  casing.  An  in- 
side patch,  applied  by  the  owner,  did  the  tire  more  harm  than  good.  The 
result,  as  shown  in  the  picture,  was  that  the  pressure  forced  the  patch 
through  the  hole,  the  patch  wedging  the  fabric  apart  and  causing  it  to 
break  almost  from  bead  to  bead.  The  inside  view  shows  how  the  patch 
has  been  pulled  away  from  its  original  position  and  has  been  forced  through 
the  break.  This  condition  results  from  the  tire  not  receiving  the  proper 
attention  when  first  cut.  An  inside  protection  patch,  used  with  an  out- 
side emergency  band  to  take  the  strain  at  the  weakened  point,  should  be 
used  until  permanent  repairs  can  be  made. 


OPERATION  AND  CARE 


245 


Skidding.— Skidding,  or  sliding  the  wheels  by  too  great  a  brake  pres- 
sure, has  a  disastrous  effect  on  tires.  Dragging  the  wheels  for  even  a 
short  distance  over  a  hard  rough  surface  will  grind  off  the  tread  and  even 
go  through  several  thicknesses  of  fabric.  There  is  nothing  to  be  gained 
by  sliding  the  wheels.  Learn  to  apply  the  brakes  up  to  the  point  where 
the  wheels  will  just  turn  and  no  farther.  The  braking  effect  will  be  just 
as  great  or  even  greater  than  if  the  wheels  are  skidded. 


FIG.  249. — Rut-worn  tire. 


FIG.  250. — Tire  injured  by  chains. 


Running  in  Ruts. — No  tire  will  stand  the  wear  from  continued  running 
in  car  tracks  or  ruts. 

Figure  249  shows  a  tire  worn  off  on  the  sides,  commonly  called  "rut- 
worn."  The  same  condition  will  result  if  a  tire  is  run  on  muddy  roads 
that  have  a  frozen  crust  insufficient  in  thickness  to  support  the  car,  so 
that  the  tire  in  breaking  through  is  bound  to  be  gouged  off  in  the  manner 
shown.  This  condition  also  results  from  running  close  to  and  rubbing 


246  THE  GASOLINE  AUTOMOBILE 

against  curbstones.     A  similar  condition,  but  nearer  the  tread,  is  caused 
by  running  in  car  tracks. 

One  can  readily  see  that  this  puts  the  side  of  the  tire  to  a  greater  test 
than  its  surface  ever  gets  in  merely  passing  over  the  road.  No  tire  will 

withstand  this  rough  treatment. 

Chain  Bruises. — Figure  250  shows  a 
tire  that  has  been  injured  by  the  use  of 
chains.  Almost  any  chain  will  injure 
a  tire  if  used  to  excess,  but  some  are 
more  injurious  than  others.  Evidently, 
the  chain  used  on  this  tire  was  fastened 
to  the  spokes;  at  least,  it  appears  that 
it  was  held  tightly  in  one  place,  as  the 
cutting  appears  at  regular  intervals. 
The  tread  is  cut  through  the  fabric 
and,  in  fact,  loosened  up  and  torn 
badly  in  places.  The  least  injury  re- 
sults from  chains  that  are  loosely  ap- 
plied and  have  play  enough  to  work 
themselves  around  the  tire,  distributing 
the  strain  to  all  points  alike.  The 
greatest  amount  of  injury  comes  from 
using  the  chains  on  hard  paved  streets, 
where  they  are  least  needed. 

Poor  Alignment. — Figure  251  shows 
a  tire  that  is  worn  to  the  fabric.  This 
is  a  very  common  condition,  and  is 
caused  by  the  wheels  being  run  out  of 
line  and  usually  occurs  on  the  front 
wheels,  affecting  both  tires  alike, 
although  sometimes  one  tire  only  is 
affected.  Improper  adjustment  of  the 
steering  apparatus,  or  a  bent  knuckle, 
cross-rod  or  axle  is  responsible.  Under 
either  of  these  conditions  the  tread  will 
wear  away  in  a  remarkably  short 
time. 

It  is  to  be  assumed  that  all  cars  are  received  from  the  manufacturer 
in  perfect  alignment,  but  after  being  run  a  while,  the  steering  gear,  if  not 
watched  very  closely,  is  apt  to  become  affected  by  wear  or  accident.  To 
aid  in  steering,  the  front  wheels  are  permitted  to  "toe  in"  just  a  little, 
but  if  allowed  to  do  so  to  any  marked  degree,  this  condition  is  bound  to 
result. 


FIG.  251.— The 
result  of  poor 
wheel  alignment. 


FIG.  252.— Re- 
sult of  under-in- 
flation. 


OPERATION  AND  CARE  247 

Under-inflation. — Figure  252  shows  the  result  of  running  a  tire  under- 
inflated,  that  is,  too  soft.  In  this  condition,  the  tire  is  being  constantly 
kneaded  by  the  road  surface  and  the  rubber  is  worked  loose  from  its  bond 
to  the  fabric.  The  wavy  condition  of  the  tread  is  due  to  this  loosening. 
Another  condition  which  is  not  visible  in  this  figure  is  rim-cutting.  There 
are  probably  more  tires  injured  from  this  cause  than  any  other.  Proper 
inflation  will  prevent  both  conditions.  There  is  a  mistaken  idea  among 
many  motorists  that  it  is  easier  on  tires  if  they  are  not  inflated  quite  to 
the  pressure  recommended.  Keep  the  pressures  up  to  those  recom- 
mended. There  is  little  danger  of  over-inflation  unless  an  air  bottle  is 
used.  The  prevailing  pressure  for  tires  is  20  Ib.  times  the  diameter  of 
the  tire.  For  example,  the  pressure  for  a  4-in.  tire  is  20  times  4,  or  80  Ib. 
Of  course,  the  pressure  should  vary  somewhat  with  the  weight  on  each 
tire,  but  if  a  car  is  properly  tired  the  above  figures  will  hold.  In  the 
absence  of  any  better  test,  a  good  rule  to  follow  is  to  inflate  to  a  sufficient 
pressure  to  prevent  the  tires  from  showing  any  depression  under  the 
weight  of  the  car  without  passengers. 

Blisters. — Small  cuts  in  the  rubber,  especially  if  they  extend  to  the 
fabric,  should  be  given  immediate  attention.  If  these  cuts  are  neglected, 
the  tread  will  work  loose  from  the  fabric,  sand  will  work  in  and  form  a 
sand  blister.  Furthermore,  water  reaches  the  fabric  and  quickly  rots  it 
so  that  a  blow-out  may  soon  result.  As  soon  as  discovered,  such  cuts 
should  be  cleaned  out  and  the  cut  filled  with  some  plastic  tire  compound 
made  for  this  purpose. 

173.  Figuring  Speeds. — In  order  to  figure  the  speed  of  any  automobile, 
it  is  necessary  to  know  three  things,  namely:  the  speed  of  the  engine  in 
revolutions  per  minute,  the  gear  ratio  or  gear  reduction,  and  the  size  of 
the  rear  wheels.  To  make  this  figuring  unnecessary  the  chart  of  Fig. 
253  has  been  produced,  from  which  the  result  can  be  taken  without  any 
actual  figuring. 

Thus,  beginning  at  the  bottom  on  the  left  hand  side,  the  diameter  of 
the  wheels  is  37  in.;  follow  vertically  up  the  37-in.  line  until  it  intersects 
the  gear  ratio  diagonal.  In  this  case  the  gear  reduction  is  3^  to  I.  The 
37-in.  line  intersects  this  diagonal  at  the  point  C. 

Then  follow  horizontally  across  to  the  right  hand  side  of  the  chart, 
where  such  a  horizontal  line  would  intersect  the  diagonals  representing 
the  speed  of  the  engine.  In  this  instance  the  engine  speed  is  taken  at 
2000  r.p.m.,  and  the  line  intersects  it  at  the  point  D.  From  this  point 
drop  a  vertical  to  the  base,  which  will  be  intersected  at  a  point  represent- 
ing the  car  speed,  in  this  case  67  miles  per  hour. 

The  table  can  also  be  used  to  find  the  engine  speed  in  revolutions  per 
minute,  knowing  the  car  speed  in  miles  per  hour  (which  can  be  read  on  the 
speedometer},  the  size  of  tires  and  the  gear  reduction.  In  such  a  case 

26 


248 


THE  GASOLINE  AUTOMOBILE 


proceed  as  before,  obtaining  the  horizontal  line  C-D  extending  across  the 
diagram.  Then  starting  on  the  right  hand  base  line,  at  a  point  indicating 
the  speed  as  67  miles  per  hour,  draw  a  line  vertically  upward  until  it 
intersects  this  C-D  line.  This  point  of  intersection  D  will  come  on  a 
diagonal,  giving  the  speed  of  the  motor.  In  this  case  it  comes  on  the 
2000-r.p.m.  line  exactly,  but  if  the  speed  were  followed  upward  from  50 
miles  per  hour,  for  instance,  another  point  would  be  obtained  not  on  any 
of  the  curves  drawn.  However,  it  would  be  midway  between  1600  and 
1400,  so  that  1500  r.p.m.  would  be  taken  as  the  motor  speed. 

B.P.M.  of  Engine 


32         34 
Wheel  diam.  in  inches 


100  90    80   70  60  50   40   30  20   10    0 
Oar  speed.    Miles  per  hour 


FIG.  253.— Speed  chart. 


174.  Interstate  Regulations. — The  lighting  requirements  of  the 
different  states  are  practically  uniform  and  call  for  two  white  lights  in 
front  and  one  red  light  in  the  rear.  It  is  usually  required  that  the  rear 
license  tag  be  illuminated  with  a  white  ray  from  the  rear  lamp.  Many 
cities  now  require  that  the  headlights  be  dimmed.  This  makes  it  desir- 
able to  inquire  regarding  such  regulations  before  driving  through  a 
strange  city. 

All  states  with  the  exception  of  Louisiana  require  the  registration  or 
licensing  of  automobiles  in  some  form,  but  the  law  in  Mississippi  has 
been  declared  unconstitutional.  The  registrations  are  renewable  an- 
nually except  in  the  District  of  Columbia,  Florida,  South  Carolina,  Ten- 


OPERATION  AND  CARE  249 

nessee,  Texas,  and  Utah,  where  they  are  perpetual,  and  in  Minnesota, 
where  they  are  for  3  years.  Professional  chauffeurs  must  be  examined 
and  licensed  in  nearly  all  states,  while  in  some  states  even  the  owner  and 
the  members  of  his  family  must  have  drivers'  licenses. 

Non-residents  of  a  state  are  permitted  to  drive  in  most  of  the  states 
for  limited  periods  without  taking  out  a  license,  providing  they  have 
complied  with  the  laws  of  their  own  states  and  providing  their  own  states 
reciprocate  in  this  respect.  These  periods  vary  from  10  days  in  New 
Hampshire  and  Rhode  Island  to  90  days  in  California  and  Colorado  and 
to  unlimited  periods  of  some  others. 

In  Oklahoma,  South  Carolina,  Tennessee  and  Texas,  non-residents 
are  not  exempt  from  registration,  but  the  fee  is  only  from  50  cents  to 
$3  for  these  states.  Oklahoma  also  permits  its  cities  to  license  and 
regulate  the  use  of  automobiles.  In  Connecticut,  non-residents  are 
permitted  to  travel  on  their  home  licenses  only  provided  they  have  two 
license  tags,  one  front  and  one  rear.  In  Louisiana,  the  entire  control  is 
left  to  the  municipalities. 

In  Alaska,  there  is  no  license  required  except  for  dealers.  In  Porto 
Rico,  non-residents  must  secure  a  license  from  the  Commissioner  of 
the  Interior.  The  fee  is  $2  per  month. 

The  motorist  must  remember  that  there  are  local  restrictions  every- 
where, which  could  not  be  given  in  the  limited  space  available  here,  even 
if  all  of  them  were  available.  For  instance,  Wisconsin,  Pennsylvania, 
New  York  City,  Detroit,  Chicago,  Province  of  Ontario,  etc.,  either  require 
a  full  stop  or  slowing  to  4  or  5  miles  per  hour  in  approaching  a  street  car 
stopping  to  let  off  or  take  on  passengers.  These  and  local  traffic  police 
restrictions  can  be  found  out  locally,  or  avoided  entirely  by  driving  slowly 
and  carefully  at  all  times,  and  in  a  manner  consistent  with  the  rights  of 
others,  particularly  of  pedestrians. 

In  case  of  accident,  the  motorist  should  always  stop,  obtain  the  names 
of  witnesses,  and  give  his  own  name  and  other  information  freely,  as  well 
as  evidence  a  willingness  to  assist,  whether  in  the  wrong  or  not. 

175.  Canadian  Regulations. — Upon  entering  the  Dominion,  the 
owner  or  operator  must  give  a  bond  for  the  re-exportation  of  the  car. 
This  is  to  prevent  cars  being  taken  in  permanently  duty-free.  In  the 
majority  of  provinces,  a  Dominion  license  and  tags  are  necessary. 

If  the  tourist  is  not  known  personally  to  the  officer  at  the  border,  he 
must  take  out  the  license  and  give  the  bond  as  mentioned  above.  But  if 
known,  he  may  be  allowed  to  enter  free  of  both  duty  and  tax  for  7  days. 

The  bond  given  must  be  for  twice  the  amount  of  duty,  if  the  stay  is 
to  be  for  less  than  6  months.  This  is  furnished  by  bonding  companies  in 
the  principal  cities  of  the  United  States  and  Canada,  and  usually  at  the 
border  line,  the  usual  fee  being  $5.  The  following  are  among  those 


250  THE  GASOLINE  AUTOMOBILE 

who  will  furnish  such  a  bond:  Guarantee  Co.  of  North  America,  111 
Broadway,  New  York  City;  J.  A.  Newport  &  Co.,  Niagara  Falls,  Ontario; 
Niagara  Falls  Auto  Transit  Co.,  Niagara  Falls,  N.  Y.;  J.  M.  Duck, 
Windsor,  Ontario;  A.  J.  Chester,  Sarnia,  Ontario.  Messrs.  Newport  and 
Duck  will  also  procure  the  license  and  permit  in  advance,  if  requested, 
the  charge  being  $4.30. 

176.  Touring  Helps — Route  Books. — The  whole  of  the  United  States 
and  the  tourable  parts  of  Canada  are  covered  by  the  Automobile  Blue 
Books.     Of  these  there  are  seven  volumes,  as  follows:  Vol.  1,  New  York 
State  and  Lower  Canada;  Vol.  2,  New  England  and  the  Maritime  Prov- 
inces of  Canada;  Vol.  3  ,New  Jersey,  Pennsylvania,  Delaware,  Maryland, 
and  Southeastern  States;  Vol.  4,  The  Middle  West  to  the  Mississippi 
River;  Vol.  5,  The  Far  West  from  the  Mississippi  to  the  Pacific  Coast; 
Vol.  6,  California,  Oregon,  Washington,  British  Columbia;  Vol.  7,  the 
Metropolitan  Guide.     They  are  published  by  the  Automobile  Blue  Book 
Publishing  Co.,  2160  Broadway,  New  York,  and  910  S.  Mich.  Ave., 
Chicago,  at  $2.50  a  volume.     There  are  also  other  good  route  books  pub- 
lished in  different  localities,  among  which  is  Kings  Guide,  which  covers 
the  north  central  states  in  great  detail.     This  is  issued  by  Sidney  J. 
King,  626  S.  Clark  St.,  Chicago. 

For  its  members,  the  American  Automobile  Association  maintains  a 
route  bureau  and  sells  a  number  of  excellent  maps. 

For  those  who  can  use  them,  the  topographical  maps  of  the  United 
States  Geological  Survey  are  most  accurate  and  very  interesting,  giving 
more  detailed  information  than  any  of  the  others,  particularly  with  regard 
to  difference  of  elevation.  Information  relative  to  them,  prices,  etc., 
may  be  obtained  from  the  Director  of  the  Survey,  Washington.  In 
some  states,  county  highway  maps  may  be  secured  from  the  state  high- 
way department. 

177.  Cost  Records. — It  is  always  a  good  plan  to  know  just  what  the 
operation  of  an  automobile  costs.     The  following  forms  are  suggested  for 
keeping  data  on  which  to  base  figures  for  the  annual  cost  statement. 
These  forms  can  be  ruled  on  the  pages  of  any  notebook  of  about  5  in.  by 
8  in.  size.    The  notebook  should  be  kept  in  the  car  so  that  complete 
records  can  always  be  made.     In  preparing  an  annual  statement  of  the 
cost,  it  is  customary  to  charge  an  annual  depreciation  of  20  per  cent  of 
the  original  cost  of  the  car.     The  total  cost  for  the  year  should  include 
this  depreciation  charge,  as  well  as  the  cost  of  gasoline,  oil,  tires,  fines, 
and    repairs.     Accessories    are    more  properly  chargeable    against   the 
capital  account  of  the  car  less  an  annual  depreciation  charge,  the  same  as 
the  car  itself.     The  cost  record  will  also  give  the  owner  a  reliable  record 
of  the  service  obtained  from  his  tires  and  the  cost  per  mile. 


OPERATION  AND  CARE 


251 


GASOLINE 

Date 

No.  of 
Gal. 

Cost 

Speedometer  readings 

Notes   on  carburetor 
adjustment 



- 

Total  ga 
Miles 

per  gal.,  a 

LUBRICATING  OIL 

Date 

Gal. 

Cost 

Speedometer  readings 

Brand  of  Oil 

Total  ga 
Miles  pe 

r  gal.,  avj 

\ 

252 


THE  GASOLINE  AUTOMOBILE 


Make- 


TIRE  RECORD 
Serial  No. Size- 


Date    on 

Date  off 

Speedometer    Reading 

Front  or  Rear 

On 

Off 

TIRE  REPAIRS 


Date 

Nature 

Cost 

Remarks 

First  Cost- 
Repairs — 


Total  Cost- 


SUMMARY 


Total  Mileage- 
Cost  per  Mile- 


NOTE:  Keep  a  separate  sheet  for  each  casing  and  tube. 


OPERATION  AND  CARE 


253 


REPAIRS 

Date 

Name 

Cost 

Remarks 

Part 

Labor 

Total  cost 

ACCESSORIES 

Date 

Name  and  Make 

Cost 

Remarks 

FINES 

Date 

Place 

Amount 

Remarks 

INDEX 


Air  cooling,  122 
Alcohol  AS  *  fuel,  TS 

heating  value,  79 

xise  in  rs<iistor,  124 
Alignment  of  wheels,  246 
Alternating  current,  127 
Ampere,  definition  of,  127 
Armature  of  magneto,  156 
At  water  Kent  ignition,  141 
Automatic  spark  advance,  151 

Atwater  Kent,  143 

Ddeo,  151 

Eisemann,  163 

Westinghouse,  146 
Axles,  dead,  12 

front .  8 

live,  13,  71 

rear,  12,  71 


B 


Batteries,  dry,  128 

storage,  128,  182,  224 
Battery  charging,  185 

connections,  129 

ignition,  130 

troubles,  224 
Bearing  troubles,  221 
Bevel  gear  drive,  71 
Bloc  cylinder  castings,  55 
Blow-outs,  tire,  244 
Bodies,  types  of,  2 
Bosch  magneto,  167 

dual  system,  170 

two-independent  system,  173 
Brakes,  16 

troubles,  230 

use  of,  233 
Buick  oil  pump,  108 

rear  axle,  73 
Burton  process,  76 


Cadillac  cooling  system,  121 

"wght ,"  engine,  60 

"four"  engine,  M 

oiling  system,  111 
Calcium  chloride,  124 
Cam  angles,  SO 

shafts,  58 

Canadian  regulations,  249 
Carburetor  adjustments,  us 

principles,  79 

troubles,  221 
Carburetors,  Carter,  97 

Holley,  86,  87 

Kingston,  90 

Marvel,  91 

Kay  field,  95 

Schobler,  82,  84 

Stewart,  89 

Stromberg,  94 

Zenith,  94 
Cars,  electric,  1 

gasoline,  2 

steam,  1 

types  of,  2 

Cells  (see  "Batteries") 
Change  gears,  66 
Charging  batteries,  185 
Chassis,  the,  2 

Ford,  48 

Hollier  "eight,"  47 

Mitchell  "eight,"  46 

Studobaker  "six,"  5,  45 

truck,  12 

Clearance  and  compression,  39 
Clutches,  64,  228 
Clutch  troubles,  228 
Coils,  vibrating,  132 

non-vibrating,  137,  156 
Cold  test  for  oils,  104 
Commercial  cars,  4 
Compression,  39,  216 


255 


256 


INDEX 


Condensers,  132,  225 
Connecticut  ignition  system,  139 

magneto,  160 
Carbon  deposits,  220 
Control  systems,  23 
Cooling  the  cylinders,  40,  117 

solutions,  123 

troubles,  227 
Cost  records,  250 
Cranking,  231 
Crank  shafts,  57 

Current,  direct  and  alternating,  127 
Cycles,  25 

four-stroke,  26 

two-stroke,  35 
Cylinder  cooling,  40,  117 

oils,  104 


Delco  ignition,  147 

starter,  190 
Depreciation,  250 
Differential  gear,  13 
Direct  current,  127 
Disc  clutch,  65 
Displacement,  piston,  39 
Distributor  system,  137 
Dixie  magneto,  166 
Drive,  final,  70 

-shaft,  69 
Driving,  232,  234 

in  city,  235 
Dry  battery,  128 

troubles,  224 
Dual  ignition,  160 

E 

Eclipse  Bendix  drive,  197,  203 
Eisemann  magneto,  161 
Electrical  definitions,  127 
Electric  cars,  1 

ignition,  39,  127,  153 

starters,  181 
Electrolyte,  184 
En  bloc  cylinders,  55 
Engine,  25 

Buda,  52 

Cadillac,  51,  60 

Ford,  53 

Franklin,  56 


Engine,  Jeffrey,  54 

tfnight,  33 

Mitchell,  55,  63 

Packard,  63 

Speedwell,  34 

Studebaker,  52 

troubles,  214,  216 

Wisconsin,  50 
Engines,  eight  cylinder,  60 

four  cylinder,  50 

four-stroke,  26 

horse  power  of,  41 

six  cylinder,  56 

twelve  cylinder,  63 

two-stroke,  35 


Feed  systems,  gasoline,  99 

Fire  test  for  oils,  104 

Firing  order,  four  cylinder,  57 

eight  cylinder,  62 

six  cylinder,  58 
Flash  point  of  oils,  104 
Flywheels,  38 
Force  feed  oiling,  111 
Ford  chassis,  48 

control,  23 

cooling  system,  119 

engine,  53 

lubrication,  106 

magneto,  174 

rear  axle,  72 

timer,  135 

transmission,  69 
Four-stroke  engine,  26 
Frames,  6 
Franklin,  cooling,  122 

engine,  56 

frame,  6 
Friction,  103 
Fuels,  75 


Gasoline,  77 

heating  value  of,  79 

mixtures,  79 

records,  251 
Gear  sets,  sliding,  66 

location  of,  44 

planetary,  67 
Glycerine  for  cooling,  124 


INDEX 


257 


Gravity  feed  system,  99 
Gray  and  Davis  starter,  193 
Grinding  valves,  217 

H 

Holley  carburetors,  86,  87 
Hollier  "eight"  chassis,  47 
Horse  power  formulas,  41 
Hydrometer,  battery,  184 
Baume",  77 


Ignition,  39 

systems,  127,  153 
troubles,  223 

Inductor  magneto,  163 


Jesco  starter,  205 


Mitchell  "eight"  chassis,  46 
engine,  63 

"six"  engine,  56 
Mixtures,  fuel,  79 
Mixture  troubles,  222 
Motors  (see  "Engines") 

starting  (see  "Starters") 
Mufflers,  40 

O 

Ohm,  definition  of,  127 
Oiling  (see  "Lubrication") 
Oil  pumps,  106 

records,  251 
Oils,  cylinder,  104 
Overhauling  the  car,  238 
Overland  oiling,  109 

cooling,  118 

valve  adjustment,  218 


Kerosene,  78 

heating  value  of,  79 
Kingston  carburetor,  90 
Knight  car,  Lyons,  49 

engine,  34 

oiling,  113 
K-W  magneto,  163 

master  vibrator,  137 

M 

Magneto,  Bosch,  167 

Connecticut,  160 

definitions,  177 

Dixie,  166 

Eisemann,  161 

Ford,  174 

K-W,  163 

Remy,  157 

troubles,  225 
Magnetos,  principles  of,  155 

high  and  low  tension,  156 
Magnets,  153 
Manifolds,  intake,  102 
Marvel  carburetor,  91 
Master  vibrators,  136 
Mechanism  of  engines,  28 
28 


Packard  engine,  63 

Parallel  battery  connections,  129 

Petroleum,  75 

Pfanstiehl  coils,  133 

master  vibrator,  137 
Piston  displacement,  39 
Planetary  gear  set,  66 
Plugs,  spark,  135 
Power  diagrams,  43 
Power,  horse,  41 

plant  and  transmission,  14,  43 
troubles,  214 

plants,  50 

Pressure  feed  systems,  100 
Pressures,  for  tires,  247 

R 

Rayfield  carburetor,  95 
Rear  axles,  12,  71 
Records,  cost,  250 
Regulations,  interstate,  248 

Canadian,  249 
Remy  battery  ignition,  149 

magneto,  157 
Repair  records,  253 
Rims,  20 
Rittmann  process,  76 


258 

Rotary  valves,  34 
Route  books,  250 


INDEX 


S 


Schebler  carburetors,  82,  84 
Series  battery  connections,  129 
Shafts,  cam,  58 

crank,  57 

drive,  69 

propeller,  69 
Silent  Knight  engine,  34 
Skidding,  236,  245 
Spark  advance,  151 

Atwater  Kent,  143 
Delco,  151 
Eisemann,  162 
Westinghouse,  146 

plugs,  135 

Speedometer  drives,  21 
Speeds,  figuring,  247 
Splash  oiling  system,  106 
Springs,  6 

care  of,  230 
Starters,  180 

Delco,  190 

electric,  181 

Gray  and  Davis,  193 

Jesco,  205 

U.  S.  L.,  204 

Wagner,  197 

Ward-Leonard,  187 

Westinghouse,  199,  200 
Starting  in  cold  weather,  222 

generator  troubles,  209 

motor  troubles,  208 

on  spark,  179 

system,  care  of,  207 
Steam  cars,  1 
Steering  gear,  10 
Stewart  carburetor,  89 

vacuum  feed  system,  100 
•Storage  batteries,  128,  181 

battery,  care  of,  209 
in  winter,  209 
troubles,  209,  224 
Stromberg  carburetor,  94 
Strut  rods,  16 
Studebaker  chassis,  5,  45 

cooling,  119 

engine,  55 

gear  set,  68 


Studebaker  ignition,  149 
oiling,  119 
starter,  199 


Thermo-syphon  cooling,  118 
Three  point  motor  support,  44 
Time  of  spark,  151 
Timers,  135 
Timing,  magneto,  176 
Tires,  19,  240 

pressures  for,  247 

records,  252 

troubles,  243 
Torque  arm,  15 

tube,  16 
Torsion  rods,  16 
Transmission  gears,  66 

location  of,  44 

planetary,  66 

troubles,  228 
Troubles,  213 
Trucks,  4 
Two-stroke  engines,  35 

U 

Unisparker,  142 
Universal  joints,  15,  69 
U.  S.  L.  starter,  204 


Valves,  30 

adjustment  of,  217 

arrangements  of,  32 

grinding,  217 

rotary,  34 

timing,  29,  219 
Vaporization,  principles  of,  76 
Viscosity  of  oils,  104 
Volt,  definition  of,  127 
Voltage  of  dry  cell,  128 

of  spark,  132 

of  storage  cell,  129 

W 

Wagner  rectifier,  186 

starter,  197 
Ward-Leonard  starter,  187 


INDEX  259 


Washing  the  car,  240  Wisconsin  engines,  50 
Water  cooling  systems,  117  oiling  system,  112 

Westinghouse  ignition  system,  144  Worm  drive,  71 

starters,  199,  200  steering  gear,  10 

Wheel  alignment,  229,  246 
Wheels,  18 

Winter  cooling  solutions,  123  Zenith  carburetor,  94 


THE  LIBRARY 
UNIVERSITY  OF  CALIFORNIA 

Santa  Barbara 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW. 


